Impressive - presentation tool with eye candy
impressive [OPTIONS...] FILES...
Impressive is a simple presentation program that displays
slideshows of PDF documents, image files or video files. Rendering is done
via OpenGL, which allows for some "eye candy" effects.
A somewhat-modern GPU (graphics processing unit) supporting OpenGL
2.0 or OpenGL ES 2.0 and appropriate drivers are required to run
Impressive.
-a <seconds> or --auto
<seconds>
Automatically advance to the next page after the given
number of seconds. Together with the -w option (described below), this
can be used to create automatic slideshows.
Note that this option will not interrupt video playback: If a video is longer
than the interval specified with --auto, it will be played until the
end, but Impressive will change to the next page directly after that.
-A <X>:<Y> or --aspect
<X>:<Y>
Specifies the display aspect ratio. Normally, Impressive
assumes that the pixel aspect ratio is 1:1 (square pixels), regardless of the
display resolution that has been set up. If a resolution has been selected
that doesn't match the display's aspect ratio, the screen will be distorted.
To overcome this, this option may be used to manually specify the display
aspect ratio, e.g. "-A 16:9". Note that this option has no effect if
the MuPDF backend is used for rendering.
-b or --noback
Disables background rendering. By default, Impressive
will pre-render all pages in a separate background thread while the
presentation runs. If this option is specified, it will instead render all
pages immediately on startup. This option has no effect if caching is disabled
(--cache none, see below).
-bare
Disables all functionality that relies on temporary
files, specifically video frame extraction using MPlayer (extracting video
frames with FFmpeg still works), PDF page title extraction, PDF hyperlinks,
and even PDF rendering for all backends except MuPDF 1.4 or newer on Unix-like
operating systems.
--box-edge <pixels>
Sets the border size (in pixels when unzoomed) of the
highlight boxes' and spotlight's smooth edges. The default value is 4 pixels;
it can be set to zero, in which case highlight boxes and the spotlight will
have hard edges.
-B <ms> or --boxfade
<ms>
Sets the duration (in milliseconds) of the highlight box
fade-in/fade-out animation. Default value: 100 ms.
-c <mode> or --cache
<mode>
Specifies the page cache mode to use. Valid options are:
none
Disables page caching altogether, only the current and
the following page will be kept in RAM. Jumping between pages will be very
slow, because Impressive will need to render the requested pages on the fly.
In addition, the overview page won't be complete until every page has been
shown at least once.
memory
Caches all page images in memory. This is the fastest
method, but it requires very large amounts of memory (about 3 MiB per page at
1024x768 resolution).
compressed or
z
Caches all page images in memory as well, but in
compressed form. This will be a little slower than memory mode, but on
pages with uniform backgrounds, this will easily reduce the required amount of
RAM by a factor of 20.
disk
Like memory, but uses a temporary file rather than
memory for storage. This is the default.
persistent
Uses a permanent cache file for caching. This file will
not be deleted when Impressive quits and will be reused on subsequent
invocations. The default name for the cache file is derived like the names for
Info Scripts (see below for an explanation), but with a .cache file
name extension instead of .info. This method is a little bit slower
than disk mode, but the time span until the overview page is fully
populated will be significantly decreased if Impressive is ran again with the
same input files and options.
The mode name may be abbreviated at will, down to one character. Thus,
--cache persistent,
-c persist and even
-cp are all
synonyms.
-C
<filename>[:<X>,<Y>] or
--cursor
<filename>[:<X>,<Y>]
This option can be used to specify an image that shall be
used as a (software) mouse cursor instead of the normal (hardware) one. It can
either be a name of an image file (typically a transparent .png) or one of the
special values "-" (dash) or "default", both
of which select a built-in cursor image. On platforms that do not support a
hardware cursor, this default cursor will also be used as a default if this
option is not used.
If the name of an external file is specified, the position of the hotspot (the
pixel inside the cursor where the actual mouse position is located) can be
specified as well, for example: --cursor mycursor.png:2,4.
--clock
If this option is enabled, the current time will be shown
instead of the elapsed time if time display is activated (with the T
key in the default control configuration). Compatible with the -M
option.
--control-help
This option will output a short help screen of how the
control configuration (keyboard and mouse bindings) work, along with a list of
all recognized events and actions and a dump of the current bindings (which is
the default configuration if no other -e/--bind or
-E/--controls options precede this option). After that,
Impressive will exit; no presentation will be started.
-d <time> or --duration
<time>
Specifies the expected run time of the presentation. The
time parameter can be either a number of seconds or a human-readable
time like 1:23 (1 minute and 23 seconds), 4:56h (4 hours and 56
minutes), 3m45s (3 minutes and 45 seconds), 5m (5 minutes) or
1:23:45 (1 hour, 23 minutes and 45 seconds).
If an expected duration is specified, Impressive will show a semi-transparent
green progress bar at the lower edge of the screen, indicating how much time
has already passed. If the time is up, the bar will occupy the whole edge and
fade to yellow (at 125% of the expected time) to red (at 150% or more).
-D <ms> or --mousedelay
<ms>
Sets the time (in milliseconds) the mouse cursor is shown
in fullscreen mode if it is not moved. There are two special values: 0 (zero)
shows the mouse cursor permanently, 1 (one) hides it completely. The default
value is 3000 ms.
--darkness <percentage>
Specifies how much the screen shall become darker when
using highlight boxes or spotlight mode. The value is specified in percent,
with 25 being the default. A value of zero would mean no darkening at all (the
screen would just be blurred slightly, and desaturated if the graphics
hardware supports it), and a value of 100 would make everything but the
highlighted parts of the screen black.
-e <bindings> or --bind
<bindings>
Configures keyboard or mouse bindings. For the syntax of
the argument, refer to the Control Configuration section of the manual.
-E <filename> or --controls
<filename>
Loads a configuration file for keyboard and mouse
bindings. For the syntax of these files, refer to the Control Configuration
section of the manual.
--evtest
If this option is specified, Impressive will not start a
normal presentation, but instead enter the so-called "Event Test
Mode" after the display has been initialized. In this mode, Impressive
will simply capture all keyboard and mouse events and display the name of the
last event on the screen. In addition, events will be logged to standard
output. This mode helps with determining the event names for each key when
creating a custom control configuration (see the Control Configuration
section).
-f
Sets the window/fullscreen mode Impressive shall start up
with. This option can be specified multiple times; each times it is found, the
next of the three options is selected, in the follwing order: (1.)True
fullscreen mode, including setting the video mode. This is the default
mode. (2.)Windowed mode, where Impressive runs in a standard window.
(3.)"Fake-fullscreen" mode, where fullscreen is emulated by
uding a window without border that fills the whole screen. Setting the display
resolution is not possible in this mode. Each of these modes has a
corresponding long option that enables it directly (--fullscreen,
--windowed and --fake-fullscreen).
--fullscreen
Starts Impressive in fullscreen mode (the default). See
the discussion of the -f option for details.
--fake-fullscreen
Starts Impressive in "fake fullscreen" mode.
See the discussion of the -f option for details.
-F <file> or --font
<file>
Impressive uses some kind of text OSD to overlay the
current page number and title (if available) on the overview page. This option
can be used to specify a TrueType font file (.ttf) to use for the OSD. If the
path specified doesn't directly point to a useable font file, Impressive will
try to search the system font directories. It assumes that all fonts are
stored below /usr/share/fonts, /usr/local/share/fonts or
/usr/X11R6/lib/X11/fonts/TTF for this purpose (the latter one is useful
for Mac OS X systems specifically). If this option is not specified, any of
DejaVuSans.ttf or Vera.ttf (the typical file name of Bitstream
Vera Sans) will be used as a default.
-g
<width>x<height>[+<posX>+<posY>]
or --geometry
<width>x<height>[+<posX>+<posY>]
Sets the screen size or resolution Impressive shall use
(in pixels). If xrandr is installed, the default screen size for
fullscreen mode is the current screen resolution; on other platforms,
Impressive uses the highest resolution available to the graphics system. If a
standard resolution cannot be determined, the default is 1024x768 pixels. This
is also the default for windowed mode.
Furthermore, if the additional parameters posX and posY are
present, they specify the position of the upper-left corner of the window
(relative to the upper-left corner of the desktop), in pixels, for windowed
and fake-fullscreen mode. The values are ignored in "true"
fullscreen mode.
-G <gamma>[:<blacklevel>] or
--gamma <gamma>[:<blacklevel>]
Sets up the startup gamma and (optional) black level
value. The black level is the original image's intensity level (0...254) that
is to be mapped to black in Impressive's output. Note that gamma and black
level adjustments may be unavailable or constrained on some systems.
-h or --help
If this option is specified, Impressive writes a short
command line help screen to standard output and does not start a
presentation.
-H or --half-screen
This option makes Impressive show the overview page and
OSD elements on the right half of the screen only. The overview page will only
show the left half of the slides as previews. Using a multi-monitor setup with
a wide virtual screen and specially crafted slides (e.g. those that can be
generated with LaTeX's beamer class), this makes it possible to have
presenter's notes on the second screen.
Note that transitions and animations are still operating on the whole screen,
making some of them (like PagePeel) look ugly. Impressive also disables
the overview zoom animation in half-screen mode; it can be re-enabled by
explicitly setting it to another value with a later command line option
(--zoomtime).
Another limitation is that the allocation of the screen halves (slides left,
overview right) is fixed.
-i <page> or --initialpage
<page>
Specifies the page number to start with. The default
value is 1 (start with the first page). If another value is specified, the
page shown by Impressive right after initialization is not the first one of
the PDF or image list. Additionally, pre-rendering (if enabled) will also
start at the specified page.
-I <filename> or --script
<filename>
Overrides automatic derivation of the info script
filename and specifies a script file directly.
--invert
This option makes Impressive invert the colors of each
page, turning black to white and vice-versa. Note that it is a full RGB
inversion, so it will, for example, turn dark green to light purple (and
vice-versa) too.
-k or --auto-progress
This option makes Impressive show a progress bar at the
bottom of the screen, visualizing the timeout on pages that have one (either
specified as a page property or using the --auto command-line option).
Nothing is done on pages that don't have a timeout.
The progress bar shown by this option takes precedence over the
--duration or --page-progress bars: If one of these options is
specified as well, the timeout progress bar will be shown on pages with a
timeout, and the other progress bar will be shown on pages without one.
-l or --listtrans
If this option is specified, Impressive writes a list of
all available transition classes to standard output and does not start a
presentation. Transitions that are enabled by default are marked with a star
(*) left of the class name.
-L <spec> or --layout
<spec>
Specifies the OSD layout. Read below for an explanation
of this option.
--maxzoom <factor>
The maximum zoom factor up to which Impressive shall
attempt to render a high-resolution image of the page when zoomed in. This can
be any real number larger than or equal to 1.0; the default is 5.0. A setting
of 1.0 causes Impressive to never render a high-resolution image for zooming;
in this case, the zoom and box-zoom modes will upscale the image, but not
enhance any details.
Note that regardless of this setting, Impressive always checks the graphics
hardware capabilities (in particular, the maximum supported texture size) and
may reduce the effective value of --maxzoom if the hardware supports
less than what has been specified.
--min-box-size <pixels>
This option sets the minimum size of a highlight box, in
pixels. Boxes that are not this many pixels wide and high are rejected in
order to prevent accidental creation of highlight boxes. The default value for
this is 30 pixels.
-M or --minutes
If this option is set, Impressive will show the on-screen
timer (activated with the T key) only with 1 minute resolution. By
default, it will show a timer with 1 second resolution.
--noblur
By default, Impressive uses a fragment shader to blur and
desaturate the image when in highlight box or spotlight mode. This is usually
the faster and nicer-looking method; however, some very old hardware
implementations can't deal with that shader and fall back to an unusably slow
software implementation. Impressive tries to detect scenarios where this would
happen and automatically falls back to a different implementation.
There might be situations where this machanism fails and Impressive tries to use
the non-functional shader anyway. In these cases, the --noblur option
can be used to enforce the fallback implementation.
-N or --nocursor
This option disables any display of a mouse cursor, i.e.
neither the system ("hardware") not bitmap ("software")
cursor is shown at any time. This is mainly useful for automated
presentations, where no mouse interaction is needed.
--noclicks
If this option is enabled, switching to the previous or
next page with the left and right mouse buttons is deactivated. The keyboard
shortcuts are unaffected from this.
Note that this option only works as intended when the default controls are used.
If the -e/--bind or -E/--controls options have
been used, --noclicks might not have the intended effect.
--nologo
This option disables the Impressive logo and version
number display. Instead, the loading screen will be just black or, if
background rendering is disabled, only the progress bar will be visible.
--nooverview
This option disables the overview page. Overview
thumbnails are not created, and the Tab that normally enters overview
mode is ignored. (More precisely, the overview-enter action is
ignored.)
--noquit
This option disables the keyboard shortcuts (Q and Esc)
that could normally quit Impressive with a single keypress. If it is used, the
only way to exit the program is the key combination Alt+F4, and accidental
quitting is no longer possible.
Note that this option only works properly if the default controls are used. If
the -e/--bind or -E/--controls options have been
used, --noquit might not have the intended effect.
-o <directory> or --output
<directory>
Do not display the presentation, but render it into a
series of PNG image files inside the specified directory. The images will be
generated in the current resolution as specified by the -g option. This
option is useful if the presentation is to be given on on a foreign PC with an
old, broken or otherwise problematic MuPDF/Xpdf/GhostScript installation: By
generating images of the PDF pages, is is made sure that no rendering bugs
will happen on the target system.
-O <mode> or --autooverview
<mode>
Enables or disables automatic derivation of whether a
page shall or shall not be shown on the overview page. This feature is based
on the fact that some LaTeX presentation packages tag all pages with a title
(that can be read by Impressive with the help of
pdftk), except those
that contain multiple reveal steps.
The following modes are available:
off
Disables automatic overview mode. All pages will be shown
on the overview page by default. This is also the default setting.
first
All pages with a PDF title will be shown on the overview
page. The purpose is to show the initial state of multi-step slides on
the overview page.
last
All pages before a page with a PDF title will be
shown on the overview page. The purpose is to show the final state of
multi-step slides on the overview page.
Again, the mode may be abbreviated arbitrarily, down to one character, just like
with the
-c option above..
-p <start>-<end> or --pages
<start>-<end>
Using this option, the range of the page displayed can be
narrowed down. The presentation will start at the first page in the range. All
pages outside of the range will not be shown on the overview page and will not
be cached. However, they can be entered manually when cycling through the
presentation. Due to the fact that these pages are uncached, preparation of
the display will take considerably longer.
-P <path> or --gspath
<path>
This option can be used to override the Xpdf /
GhostScript path autodetection. The full path to the executable of either
GhostScript (gs or gs.exe) or Xpdf's pdftoppm utility
must be specified.
-q or --page-progress
If this option is enabled, Impressive will show a
light-blue semi-transparent progress bar at the lower edge of the screen that
shows the position inside the presentation, i.e. the relation between the
current page number and the total number of pages. Note that this progress bar
will not be shown if the duration progress bar (-d option) is also
enabled.
-Q or --autoquit
If this option is specified, Impressive quits
automatically when trying to navigate to the page after the last page or the
page before the first page.
This option does not have any effect if --wrap is used.
-r <n> or --rotate <n>
Display all pages rotated by nx90 degrees
clockwise. Try -r 1 or -r 3 if there are problems with PDFs
generated by LaTeX on some Xpdf or GhostScript versions.
-s or --scale (image input only)
If a directory with image files is used as input,
Impressive will scale down images that are too big for the screen. But by
default, it will not scale up smaller images to fit the screen; it will leave
a black border instead. This option overrides this setting and enables
upscaling of smaller images.
-s or --supersample (PDF input only)
This switch enables antialiasing by 4x supersampling
instead of the normal multisampling method used by Xpdf or GhostScript. While
this usually degrades both visual quality and performance, it may be necessary
for circumventing white strips or moire-like patterns in gradients.
-S <pixels> or --fontsize
<pixels>
This option sets the size, in pixels, of the OSD font.
The default value is 14.
--spot-radius <pixels>
This option sets the initial radius of the spotlight, in
pixels. The default value is 64.
--time-display
This option enables display of the elapsed presentation
time, as if the T key has been pressed immediately after startup. This
implies time tracking mode (--tracking option).
-t <ms> or --transition
<trans1[,trans2...]>
Using this switch, the set of transitions Impressive will
randomly draw at page changes can be specified. If only one transition class
is specified, this class will be used for all pages that do not have another
transition explicitly assigned in their page properties. Multiple transitions
have to be separated by commas; they will be used in random order. The
-l option can be used to get a list of available transitions.
-T <ms> or --transtime
<ms>
Sets the duration (in milliseconds) of page transitions.
0 (zero) disables transitions altogether. Default value: 1000 ms.
--tracking
This option enables time tracking mode. In this mode, a
report of all pages visited with their display duration, enter and leave times
will be written to standard output. This can be very useful when preparing
presentations.
-u <seconds> or --poll
<seconds>
If this option is specified, the source file or directory
will be checked for changes regularly. If a change in the input PDF file or
any of the image files in the input image directory is detected, the page
cache will be flushed and the current page as well as the info script will be
reloaded. The current page's transition will be shown between the old and the
new version of the page.
The new PDF file must have at least as much pages as the old one; also, it
should have the same aspect ratio. If the input is a directory, image files
must not have disappeared.
-v or --verbose
This option makes Impressive more verbose, i.e. it will
print slightly more informational messages than usual.
-V <pixels> or --overscan
<pixels>
PDF files often contain tiny amounts of white borders
around the edges which look bad in screen presentations. To eliminate this
problem, Impressive uses "overscan": PDF files will not be rendered
to fit the screen size exactly, but they will be rendered a bit larger so that
the (possibly broken) borders can be cropped off. The amount of overscan, in
screen pixels, can be set with this option. The default value is 3 pixels,
which should remove borders in most presentations at most common screen
resolutions without cropping the pages too much.
-w or --wrap
If this option is set, Impressive will "wrap"
over to the first page after the last page. In other words, advancing to the
next page at the end of the presentation will restart the whole
presentation.
-W or --nowheel
By default, it is possible to change pages using the
mouse wheel. This option disables this behavior, which can be useful to
prevent spurious page changes if the mouse wheel is likely to be moved by
accident. In addition, it makes it possible to enter zoom mode with the mouse
wheel.
Note that this option only works properly if the default controls are used. If
the -e/--bind or -E/--controls options have been
used, --nowheel might not have the intended effect.
--windowed
Starts Impressive in windowed mode. See the discussion of
the -f option for details.
-x or --fade
This option enables a smooth fade-in effect at the start
of the presentation and a fade-out effect just before Impressive quits.
-X or --shuffle
If this option is enabled, the input files will be
shuffled into random order before starting the presentation. The individual
pages of PDF input files will stay in their original order, though, so this
option is mainly useful for image presentations.
-y or --auto-auto
This option can be used together with --duration
to have Impressive compute a page timeout (as with the --auto option)
automatically. This results in a presentation that runs automatically,
displaying each slide for the same time, so that the desired total duration
will be reached (almost) exactly. One exception is the runtime of videos,
which is not taken into account.
--zbox-edge <pixels>
Sets the border size (in pixels when unzoomed) of the
box-zoom boxes' smooth edges. The default value is 1 pixel; it can be set to
zero, in which case the box-zoom area will have a hard edge.
-z <factor> or --zoom
<factor>
Sets the scaling factor that is used in zoom mode. It can
be any real value above 1.0; the default value is 2.0. Note that it might not
be possible to get high-quality zooming for large zoom factors due to hardware
restrictions. Furthermore, please be aware that after leaving zoom mode, the
image quality of the normal page display may be slightly degraded until
another page is displayed if a zoom factor other than 2.0 is used.
--zoomdarkness <percentage>
Specifies how much the non-selected parts of the screen
shall become darker in box-zoom mode. The value is specified in percent, with
90 being the default. A value of zero would mean no darkening at all (parts
outside of the zoom box would still be perfectly visible), and a value of 100
would make everything but the selected region black.
-Z <ms> or --zoomtime
<ms>
Sets the duration (in milliseconds) of the overview page
zoom-in/zoom-out effects. Default value: 250 ms.
--cachefile <filename>
Activates persistent cache mode and specifies the name of
the cache file to use.
Following the options, the input file name(s) must be specified.
Recognized file types are PDF, image files (JPEG, PNG, TIFF, BMP, PGM/PPM)
and video files (AVI, MOV/MP4, MKV/WebM, OGV, MPEG, M2TS, FLV). If the name
of a directory is put on the command line, all recognized image files (no
PDF files!) in this directory will be played in alphanumeric order
(case-insensitive).
In addition, Impressive can use a text file containing a list of
files or directories to show: This text file must contain at most one file
name per line; every character after a hash sign (#) is treated as a
comment and will be ignored. If such a comment is put on the same line as an
image file name, it will be used as the page's title. List file names must
be prefixed with an at sign (@) on the command line, e.g.
impressive @my_list_file.
Impressive will also expand wild-card characters (* and
?) if this isn't already done by the shell, but apart from that, it
will not reorder the arguments. Thus, it will show the documents in the
order specified at the command line.
If video files are specified on the command line, Impressive
generates presentation pages for them just like it does for image files. If
FFmpeg or MPlayer are installed, the page will be shown as a screenshot of
the first video frame. When entering such a page, the video will be played
back if a suitable player (MPlayer, or omxplayer on Raspberry Pi) is
installed.
The OSD layout option (-L/--layout) accepts a string
with comma-separated key=value pairs. The following
keywords are recognized:
alpha
The opacity of the OSD text, either as a floating-point
value between 0 and 1 or a percentage between 2 and 100.
margin
The distance (in pixels) of the OSD text to the screen
borders.
time
The position of the timer.
title
The position of the page title in overview mode.
page
The position of the page number in overview mode.
status
The position of the status line.
The position specifications are composed by one character that indicates whether
the text shall be displayed at the top (T) or bottom (B) edge of
the screen and one character that indicates whether it shall appear on the
left (L), on the right (R) or centered (C).
For example, the default OSD layout equals the following option
string:
-L margin=16,alpha=1,time=TR,title=BL,page=BR,status=TL
The following examples illustrate some typical command lines. They
assume that Impressive can be run by simply typing
"impressive" on the command line. Depending on how
Impressive is installed, this has to be substituted with the actual way to
run Impressive (e.g. "python
~/impressive/impressive_dev.py" for a fresh SVN checkout).
Furthermore, the file "demo.pdf" is used as the document to
show here; obviously this has to be replaced by the path to the actual PDF
file too.
In the simplest case, Impressive is run directly with the name of
the file to show and no further parameters. This will start a full-screen
presentation with all settings at their defaults:
impressive demo.pdf
To just quickly check a slide deck, it might make sense to run
Impressive in a small window and not full-screen. This can be done with
something like
impressive -f -g 800x600 demo.pdf
Impressive can also be used in digital signage scenarios, like
displays in shop windows with a permanent slideshow. This can be achieved by
having Impressive advance to the next page automatically after a specified
time (e.g. 10 seconds) and re-start the presentation from the start after
the last slide:
impressive -a 10 -w demo.pdf
On startup, Impressive will display a black screen with the
program logo at the center. If caching is enabled, but background rendering
is disabled, all pages of the presentation will then be rendered once. A bar
in the lower half of the screen displays the progress of this operation. Any
key or mouse click (except for those that quit Impressive, typically Q and
Esc) skips this process, with the effect that Impressive will render the
remaining pages on demand. Please note that the overview page will not be
complete until every page has been rendered at least once. In other words,
if the precaching process was skipped, placeholders will be displayed for
all pages that have not been rendered yet. By default, Impressive will build
up the cache in the background while the presentation runs. Thus, the
progress bar will not appear and the preparation will only take the amount
of time required to render the first two pages of the presentation. After
this initialization process, Impressive will switch to the first page
directly and without any transition.
The keyboard and mouse controls used by Impressive are
configurable (with very few exceptions). The default controls are as
follows:
Esc key
Return from the currently active special mode (zoom,
box-zoom, overview, spotlight, highlight boxes); if no such special mode is
active, quit Impressive altogether.
Q key or Alt+F4
Quit Impressive immediately.
LMB (left mouse button), mouse wheel down, Page Down
key, Cursor Down key, Cursor Right key or Spacebar
Go to the next page (using a transition).
RMB (right mouse button), mouse wheel up, Page Up
key, Cursor Up key, Cursor Left key or Backspace
key
Go to the previous page (using a transition).
Home key / End key
Go directly to the first or last page of the
presentation.
Ctrl key (modifier)
If one of the page navigation keys (Page Up/Down, Cursor
keys, Space, Backspace, Home, End) is pressed while the Ctrl key is held down,
the destination page will be entered immediately, without a transition.
L key
Return to the last (most recently displayed) page. This
can be used to toggle back and forth between two pages.
F key
Toggle fullscreen mode.
Tab key
Zoom back to the overview page. While in overview mode, a
page can be selected with the mouse and activated with the left mouse button.
The right or middle mouse button or the Tab key leave overview mode
without changing the current page.
MMB (middle mouse button)
In normal display mode, this acts like the Tab key: it
zooms back to the overview page. If the page is zoomed in, it will return to
normal mode.
LMB over a PDF hyperlink
Jump to the page referenced by the hyperlink. Two types
of hyperlinks are supported: Links that point to some other page of the same
document, and URL hyperlinks like Web links and e-mail addresses. This feature
is only available if pdftk is installed. Furthermore, xdg-open
from the freedesktop.org Portland project is required for URL links to work.
Please note that the hyperlink feature will not work properly when pages are
rotated.
click&drag with LMB (left mouse button)
Create a new highlight box. While at least one highlight
box is defined on the current page, the page itself will be shown in a darker,
blurry and (if supported by the graphics hardware) desaturated rendition. Only
the highlight boxes will be displayed in their original lightness, sharpness
and color saturation.
If a page with highlight boxes is left, the boxes will be saved and restored the
next time this page is shown again.
click&drag with Ctrl+LMB (left mouse button)
Draw a box to zoom into. This enters so-called
"box-zoom" mode, where the selected region is zoomed into full view
and anything else is displayed in much darker colors (but not blurred like in
highlight box mode). The page contents will be re-rendered in a higher
resolution, if possible (limited to what has been configured with the
--maxzoom command-line option, and the graphics hardware's maximum
supported texture size). To leave this mode again, use RMB, MMB
or Esc.
Note that box-zoom mode is mutually exclusive with highlight boxes and the
spotlight; if any of those is currently active, it's not possible to draw a
zoom box.
RMB (right mouse button) over a highlight box
If the right mouse button is clicked while the mouse
cursor is above a highlight box, the box will be removed. If the last box on a
page is removed, the page will turn bright and sharp again.
S key
Save the info script associated with the current
presentation. The main purpose for this is to permanently save highlight boxes
or keyboard shortcuts, so they will be restored the next time this
presentation is started.
T key
Activate or deactivate the time display at the
upper-right corner of the screen. If the timer is activated while the very
first page of the presentation is shown, it activates time tracking mode, just
as if the command-line option --tracking had been specified.
R key
Reset the presentation timer.
C key
Removes ("clears") all highlight boxes from the
current page.
Return key or Enter key
Toggle spotlight mode. In this mode, the page is darkened
in the same way as if highlight boxes are present, but instead of (or in
addition to) the boxes, a circular "spotlight" will be shown around
the mouse cursor position, following every motion of the mouse cursor.
+ / - key, 9 / 0 key or mouse wheel in
spotlight mode
Adjust the spotlight radius.
Ctrl+9 or Ctrl+0 keys
Resets the spotlight radius to the default value, i.e.
the value that has been set up by the radius page property, the
--spot-radius command-line option or Impressive's built-in
default.
7 / 8 key
Adjust the amount of darkening applied to the page in
spotlight, highlight box or box-zoom mode.
Ctrl+7 or Ctrl+8 keys
Resets the amount of darkening in spotlight, highlight
box and box-zoom mode to the default values, i.e. the value that have been set
up by the darkness and zoomdarkness page properties, the
--darkness and --zoomdarkness command-line options or
Impressive's built-in defaults.
Z key
Toggle zoom mode. When this key is first pressed, the
current page will zoom in. The page will be displayed at double size, but in
its original resolution (i.e. it will be blurry). Impressive will re-render
the page at the new resolution if the graphics hardware supports it. During
this time, Impressive will not accept any input, so don't even think
about clicking the mouse or pressing keys before the image gets crisp again.
In zoom mode, all other functions will work as normal. Any operations that leave
the current page, such as flipping the page or entering the overview screen,
will leave zoom mode, too.
[ / ] key
Adjust the gamma value of the display (might not be
supported on every hardware).
{ / } key
Adjust the black level of the display (might not be
supported on every hardware).
\ key
Revert gamma and black level back to normal.
O key
This will toggle the "visible on overview page"
flag of the current page. The result will not be visible immediately, but it
can be saved to the info script (using the S key) and will be in effect
the next time the presentation is started.
I key
This will toggle the skip flag of the current page. A
page marked as skipped will not be reachable with the normal forward/backward
navigation keys.
B / W key or . (dot) / , (comma)
key
Fade to black or white, respectively. This feature can be
used if a whiteboard or blackboard in front of the projection area is to be
used during the presentation. Using these two keys, the screen will fade into
a solid color. On any keypress or mouse click, it will fade back to normal.
These keys are not available in overview mode.
click&drag with MMB (middle mouse button) or RMB
(right mouse button) in zoom mode
Move the visible part of the page in zoom mode.
mouse wheel up / down in zoom mode, U key
Zoom a bit in or out. When zoomed out fully, zoom mode is
left; note that in the default configuration, this means that when trying to
zoom out even more using the wheel, the page is left instead. This is
different if the -W/--nowheel option is used, where page
navigation using the mouse wheel is disabled, and the wheel is always used for
zooming. In this mode, the wheel can also be used to enter zoom mode in the
first place.
Note that changing the zoom level on the fly with the wheel does not make
Impressive automatically re-render the page at a higher resolution to increase
the level of detail. To do this, the U key needs to be pressed manually
when the desired zoom level has been set up.
Cursor keys in overview mode
Navigate through pages.
Alt+Tab keys
If Impressive is in fullscreen mode, the window will be
minimized so that other applications can be used.
Any alphanumeric (A-z, 0-9) or function key (F1-F12) that is not
bound to a specific action mentioned above or configured by the user (see
below) can be used to assign shortcuts to pages that require quick access.
If one of the keys is pressed together with Shift, the currently
displayed page is associated with this key. To recall the page later, it is
sufficient to press the shortcut key again. Shortcuts can be stored
permanently with the S key.
As already mentioned in the previous chapter, the keyboard and
mouse bindings of Impressive can be widely configured. The only exceptions
are the Alt+F4 and Alt+Tab key combinations that
will always quit or minimize Impressive, respectively. For everything else,
there is a versatile configuration system in place; the controls described
in the previous section are merely the defaults.
Impressive's control system works by associating events
with actions. An event is a key on the keyboard, a mouse
button or a mouse wheel movement. An action is something that is
performed by Impressive as a result of an event, like going to the next
page, switching to overview mode or quitting the program. The association of
an event to an an action is called a binding. Multiple events can be
bound to the same action (like the page down and space keys in the default
setting, both of which go to the next page); furthermore, multiple actions
can be bound to the same event. In fact, bindings do not associate events
with single actions at all, but with chains of actions. Only the
first action in the chain that matches (i.e. makes sense in) the
current context will be executed if the event fires; all other actions will
be ignored. If no action matches, no action will be performed and the event
will be ignored.
One example of such an action chain is the default binding for the
left mouse button, which draws a highlight box if the mouse cursor moved, or
visits a hyperlink if the mouse cursor hovers over one, or goes to the next
page if none of the other conditions are met.
Both events and actions have mnemonic names that are used in the
command-line options and configuration files used for setting up bindings.
Event and actions names are generally case-insensitive, though the canonical
notation is lowercase.
If an event or action specified on the command line or in a configuration file
is not recognized by Impressive, an error message will be written to the
console and the offending event or action will be ignored. Errors in control
configuration are thus always non-fatal.
Keyboard events are generally named after the keys they refer to.
Consequently, the events a to z and 0 to 9 mean
the respective letter and number keys on the main keyboard, f1 to
f12 are the function keys and kp0 to kp9 are the number
keys on the numerical keypad. All of these are raw scancodes, which has two
implications: First, the key names are not internationalized and refer to
the US keyboard layout (e.g. the Z key on a German or French keyboard
will actually react to the event name y or w); second,
modifiers will be ignored as well (e.g. the numerical keypad will always
generate the kpX scancodes, even if Num Lock is off).
The mnemonic names for the other keyboard events are as follows
(in alphabetic order): ampersand, asterisk, at,
backquote, backslash, backspace, break,
capslock, caret, clear, comma, down,
end, escape, euro, exclaim, greater,
hash, help, home, insert, kp_divide,
kp_enter, kp_equals, kp_minus, kp_multiply,
kp_plus, lalt, last, lctrl, left,
leftbracket, leftparen, less, lmeta,
lshift, lsuper, menu, minus, mode,
numlock, pagedown, pageup, pause, period,
plus, power, print, question, quote,
quotedbl, ralt, rctrl, return, right,
rightbracket, rightparen, rmeta, rshift,
rsuper, scrollock, semicolon, slash,
space, sysreq, tab, underscore, up. The
events prefixed with kp_ refer to keys on the numerical keypad. Other
than that, the names should be reasonably descriptive, so they will not be
described futher at this point. Also note that not all keyboards and
platforms support the full range of keys defined in this list.
Mouse event names are mapped as follows:
lmb
the left mouse button
mmb
the middle mouse button
rmb
the right mouse button
wheelup
scrolling the mouse wheel upwards
wheeldown
scrolling the mouse wheel downwards
btnX (i.e. btn6, btn7, ...)
additional mouse buttons, the mapping of which is
device-specific; use --evtest to see which button is which
The event names can be prefixed with the three modifiers
ctrl+, alt+ and shift+ to make the event valid only if
the specified set of modifiers is pressed as well. This works for both
keyboard and mouse events. Multiple modifiers can be combined, but the order
must match the one mentioned in this paragraph. For example,
ctrl+shift+x is a valid event name, while shift+ctrl+x is
not.
A simple way to determine the name associated with an event is
using Impressive's "Event Test Mode" by invoking impressive
--evtest. In this mode, the name of each incoming event will be
displayed on the screen (and logged to standard output), which makes it
possible to determine event names by experimentation.
The following list describes all actions supported by Impressive,
together with the conditions under which they will match. Note that most
actions will not match in overview mode and during video playback, unless
mentioned otherwise in the description.
box-add
Draw a highlight box if the mouse has been moved since
the button has been pressed down. This action must only be bound to a mouse
button event, otherwise it will not function properly.
box-clear
Removes all boxes from the current page.
box-remove
Removes the highlight box under the mouse cursor, if
there is any.
box-zoom
Define a region to zoom into by drawing a rectangle. This
action must only be bound to a mouse button event, otherwise it will not
function properly.
box-zoom-exit
If in box-zoom (but not normal zoom) mode, leave box-zoom
mode.
fade-less, fade-more
Decrease or increase the amount of darkening applied to
the background in spotlight or highlight box mode.
fade-reset
Resets the background darkness in spotlight or highlight
box mode to its default value.
fade-to-black, fade-to-white
Fades to a black or white screen. Once the screen is
faded out, any event except those bound to the quit action will just
leave fade mode and not perform its assigned action.
fullscreen
Toggle fullscreen mode on platforms that support
it.
gamma-decrease, gamma-increase
Decrease or increase the gamma level (i.e. roughly the
brightness) of the display on platforms that support it.
gamma-bl-decrease, gamma-bl-increase
Decrease or increase the black level of the display on
platforms that support it.
gamma-reset
Reset the gamma and black level settings to their
defaults.
goto-end, goto-end-notrans
Go to the last page of the presentation, with or without
a transition.
goto-last, goto-last-notrans
Go to the last (i.e. most recently) visited page, with or
without a transition.
goto-next, goto-next-notrans
Go to the following page of the presentation, with or
without a transition.
goto-prev, goto-prev-notrans
Go to the previous page of the presentation, with or
without a transition.
goto-start, goto-start-notrans
Go to the first page of the presentation, with or without
a transition.
hyperlink, hyperlink-notrans
Navigate to the hyperlink under the mouse cursor, if
there is one. If the hyperlink is a reference to another page of the
presentation, this page will be activated with or without a transition. If the
hyperlink refers to an external object (e.g. an URL), it will be opened
externally, if supported by the system.
overview-confirm
When in overview mode, confirm the selection and leave
overview mode, navigating to the selected page.
overview-down, overview-up
When in overview mode, select the page above or below the
currently selected one in the grid.
overview-enter
When not in overview mode, zoom out of the current
page, entering overview mode.
overview-exit
When in overview mode, leave overview mode, zooming back
to the page that has been displayed before entering overview mode.
overview-next, overview-prev
When in overview mode, select the following or previous
page.
quit
Quits Impressive immediately. This action is available in
all modes.
save
Save or update the Info Script for the current
presentation.
spotlight-enter
If spotlight mode is not active, enable spotlight
mode.
spotlight-exit
If spotlight mode is active, deactivate spotlight
mode.
spotlight-grow, spotlight-shrink
When in spotlight mode, increase or decrease the radius
of the spotlight.
spotlight-reset
When in spotlight mode, reset the spotlight radius to the
default value.
time-reset
Reset the presentation timer.
time-toggle
Toggle on-screen display of the current presentation
time, or wall-clock time if the --clock option is used. If this is done
at the start of the presentation, before the first page has been left, time
tracking mode will be enabled, like the --tracking option would have
done.
toggle-overview
This toggles the "page is visible on overview
screen" flag for the current page. This will not have an immediate
effect, but it can be saved to an Info Script.
toggle-skip
This toggles the "skip page when navigating with
goto-prev and goto-next" flag for the current page.
video-pause
In video playback mode, this pauses or unpauses
playback.
video-seek-backward-10, video-seek-backward-1,
video-seek-forward-1, video-seek-forward-10
In video playback mode, seek forward or backward by 1 or
10 seconds.
video-step
In video playback mode, if playback is paused, advance
one frame in the video.
video-stop
In video playback mode, stop playback and return to
normal page display mode.
zoom-enter
If not in zoom mode, enter zoom mode with the zoom level
configured with the -z/--zoom option.
zoom-exit
If in zoom or box-zoom mode, leave that mode.
zoom-in, zoom-out
Slightly increase or decrease the current zoom level.
This does not change the page's rendering resolution, it only zooms the
visible part of the screen in or out, centered around the mouse cursor's
position. Zoom mode is left automatically if the zoom level goes to down to
1x; conversely, zoom mode is entered when calling zoom-in while zoom
mode is not active.
zoom-pan
If in zoom mode, the visible area of the page can be
moved around with the mouse while the key or mouse button of the associated
event is held down.
zoom-update
If in zoom mode, re-render the current page in a
resolution that best fits the current zoom level, up to the limits of the
graphics hardware or the --maxzoom setting. This only needs to be done
explicitly when zooming with the zoom-in action; zoom-enter and
box-zoom do this automatically.
The arguments of the -e/--bind command-line option
have the following basic syntax:
<event> [,<event2>...]
<operator> <action>
[,<action2>...]
In other words, it is a sequence of event names joined with commas, followed
by an operator (see below) and a sequence of action names joined with
commas. Multiple such binding statements can be combined into one argument
by joining them with a semicolon (;).
The used operator defines in which way the action list shall
modify the bindings of the referenced events:
= (equals sign), += (plus sign and equals sign)
The specified actions will be added to the
bindings of the specified events. In other words, event=action1,action2
does exactly the same as event=action1; event=action2.
:= (colon and equals sign)
The specified actions will replace the bindings of
the specified events.
-= (minus sign and equals sign)
The specified actions will be removed from the
bindings of the specified events. For example, to make the Esc key in
the default bindings not clear highlight boxes, but otherwise preserve its
original functionality, escape -= box-clear can be used.
Other than bindings, a statement can also contain one of the
following special commands:
clearall
Clears all current bindings.
defaults
Discards all current bindings and (re-)establishes the
default bindings.
include <filename>
Loads and executes a control configuration file with a
specified name.
The syntax for the configuration files used with the
-E/--controls option or include statement is exactly
the same as for the ad-hoc configuration option, except that individual
bindings can be written on individual lines instead of joining them together
to a single long line with semicolons. In addition, everything following a
hash sign (#) on a line will be ignored as a comment.
One practical example for such a configuration file can be the
following: The author of this program uses a cheap presentation remote
control device that has four cursor keys, one "enter" key and a
slider that switches between keyboard and mouse mode. Mouse mode works as
expected, but what it does in keyboard mode is quite peculiar: the up and
down keys act like Page-Up and Page-Down keys on a keyboard, the right arrow
key sends the letter B to the computer, and the left key toggles
between Esc and F5 each time it's pressed. The following
configuration file allows basic navigation and access to overview mode with
this device:
clearall # don't use the default bindings
lmb = quit # quit Impressive by clicking in mouse mode
# everything else uses keyboard mode:
return = overview-enter, overview-confirm # toggle overview mode
escape, f5 = overview-prev, goto-prev
b = overview-next, goto-next
pageup = overview-up, goto-prev
pagedown = overview-down, goto-next
To get a better idea of how the control configuration system works
in practice, it's recommended to study the output of impressive
--control-help - this not only gives a concise overview of all events
and actions, but also a full dump of Impressive's default bindings that can
be used as a starting point for own customizations.
Impressive offers a powerful way to customize individual
presentations using so-called info scripts. An info script is a text file
having the same name and located in the same directory as the presentation
file itself, except for the additional suffix .info. Thus, a
presentation file called BrandNewProduct.pdf would have a info script
with the name BrandNewProduct.pdf.info. If multiple arguments were
specified on the command line, the info script will be called just
.info (a dot file, so to speak). If a directory name was specified as
the only argument, either a file called DirectoryName.info or
a file called .info inside the directory will be used,
depending on whether a path separator was specified at the end of the
directory name or not - Impressive simply appends .info to whatever
the input path name was.
In any case, the default file name can be overridden by the -I command
line option.
Info scripts are actually Python scripts with full access to
Impressive's global data structures and functions. (It is possible to write
real interactive applications using info scripts.) Thus, they can modify a
broad range of settings concerning Impressive. This manual will only cover
the most basic ones.
The main part of an info script defines the properties of each
page. At the moment, the following properties are defined:
title
Each page can have a title that is displayed in the
Impressive window's title bar. If there is no title explicitly specified in
the info script, the title of the page will be extracted from PDF metadata if
pdftk is installed, or the image file name will be used if the presentation is
an image slideshow.
transition
With this property, the transition class to be used for
rendering the transition to this page (i.e. between the previous page and this
page) can be specified. For pages lacking this property, random transitions
will be chosen. A list of available transition classes can be obtained with
impressive -l.
transtime
This property overrides the global transition time
parameter (-T at the command line). It contains the integer time (in
milliseconds) the transition to this page shall take.
overview
This property holds a boolean value (0/False or
1/True) that specifies whether the page shall be included in the
overview page. If this property isn't specified, it is assumed to be
True.
skip
This boolean property can be set to 1/True if the
page shall be skipped during the presentation.
Pages with overview:True, skip:False will be accessible both by cycling
through the pages and using the overview page,
pages with overview:True, skip:True will be silently skipped in the
normal page cycle, but remain accessible from the overview page,
pages with overview:False, skip:False will appear in the normal cycle,
but not on the overview page
and pages with overview:False, skip:True will not be accessible at
all.
boxes
This property stores a list of highlight box coordinates.
Normally, there is no need to edit this by hand, as Impressive handles this
automatically if the S key is pressed.
timeout
If a timeout property is present and the page is
shown, Impressive will automatically switch to the next page after the
specified number of milliseconds. Normally, the timeout will only be effective
the first time the page is shown unless wrap mode is used (command-line option
-w or --wrap). This restriction makes it possible to create
self-running presentations with individual per-page timeouts.
radius
This property takes an integer value that, if defined,
will be used to set a new spotlight radius every time the page is entered.
This overrides the current setting as defined by the --spot-radius
command line option or run-time adjustments. Note that the value is not
reset to the default value after the page has been left again.
darkness
This property takes an integer or floating-point
percentage value that, if defined, will be used to set the background darkness
in spotlight or highlight box mode each time the page is entered. This
overrides the current setting as defined by the --darkness command line
option or run-time adjustments. Note that the value is not reset to the
default value after the page has been left again.
zoomdarkness
This property takes an integer or floating-point
percentage value that, if defined, will be used to set the background darkness
in box-zoom mode each time the page is entered. This overrides the current
setting as defined by the --zoomdarkness command line option or
run-time adjustments. Note that the value is not reset to the default
value after the page has been left again.
comment
This property can hold a string with a single line of
text that will be displayed on screen while the page is shown. Display of this
text can not be disabled.
sound
Specifies the file name of a sound file to be played (via
MPlayer) when the page is first entered. Once started, the sound will be
played until its end is reached, another sound or video is played, or
Impressive is exited.
video
Specifies the file name of a video file to be played when
the page is first entered. The video will be displayed full-screen. Any key or
mouse click stops playback, except the cursor keys, which are used to seek in
the video file, and space, which can be used to pause playback.
Please not that this function is still somewhat experimental. It uses an
external player application (MPlayer, or omxplayer on Raspberry Pi) to perform
the actual playback, and embeds it into Impressive's window.
always
If this property is present and set to 1 or True,
the media file specified in the sound or video properties will
be played every time the page is entered, not just the first time.
progress
If this property is set to zero, the presentation
progress bar (which is usually set up with the -d/--duration
command line switch) will not be shown on this page. In practice, it might be
useful to hide the bar from the first page so that it is not visible during
the introduction.
reset
If this property is set to 1 or True, the timer
will be reset each time this page is left, just as if the R has been
pressed. If the special value 2 or FirstTimeOnly is used, the reset
will only take place if the page was shown for the first time. Again, this is
particularly useful on the first page: A combination of progress:False,
reset:FirstTimeOnly makes it possible to set up the presentation long
before it actually begins - the first page can be showed as long as desired,
actual timing starts at the second page.
rotate
This property is a per-page override of the global
-r command line option: It specifies how the page shall be rotated, in
90-degree steps clockwise.
OnEnter, OnLeave, OnEnterOnce,
OnLeaveOnce
These properties can contain a Python callable (i.e. a
function reference or lambda expression) that is executed when the page is
entered or left. The ~Once variants will only be executed when the page
is entered or left for the first time. The callable must not take any
arguments. This feature can be used to associate arbitrary Python code with
specific pages, for example to execute external programs.
Warning: Lambda expressions cannot be properly processed by the Info
Script save function (S key). If Impressive encounters lambda
expressions when saving, it will remove them. In addition, it will not
overwrite the original info script, but generate an extra file that needs to
be merged withe the original script by hand.
keys
This property can be assigned a dictionary that maps
alphanumerical keys to Python functions. For example, 'keys': { 'x':
SomeFunction } will invoke SomeFunction() if the lowercase
character 'x' is typed while the page is displayed. Regarding the functions,
the same restrictions as for the OnEnter/OnLeave family apply:
the function must not take any parameters and lambda functions can not be
saved. Also note that it is not possible to overwrite Impressive's pre-defined
key bindings with this method.
invert
This property specifies whether the colors of that page
shall be inverted in the same way the --invert command-line switch
does. It overrides the --invert setting on a per-page basis: If set to
True, the page will always be inverted; if set to False, the
page will never be inverted even if --invert has been specified on the
command line.
Note that in Impressive versions prior to 0.11.0, the
transition and transtime properties defined the transition
from the current page to the next, not from the previous page to the current
one.
The properties are stored together in a Python dictionary called
PageProps. The syntax looks like in this example:
PageProps = {
1: {
'title': "Title Page",
'transition': PagePeel,
'sound': "background_music.mp3"
},
2: {
'title': "Another Page",
'timeout': 5000
}
}
The PageProps definition (and only the PageProps
definition) will be rewritten by Impressive if the S key is pressed.
User-defined PageProps entries will also be left untouched, except for some
pretty-printing.
The name of the presentation is shown in the title bar of the
Impressive window (if not in fullscreen mode). By default, the file name or
(if available) PDF metadata title will be used for this purpose, but the
presentation title can also be explicitly set by overwriting the
DocumentTitle variable:
DocumentTitle = "My Presentation"
Another useful variable, AvailableTransitions, contains a
list of all transition classes that may be used for randomly assigning
transitions to pages lacking the transition property. Thus, if a
certain transition is undesired (either because of personal dislike or
because it shall be used exclusively on pages where it is manually assigned
using PageProps), something like the following can be written:
AvailableTransitions.remove(WipeBlobs)
On the other side, it's possible to activate transitions that are not enabled
by default:
AvailableTransitions += [SlideUp, SlideDown]
Alternatively, AvailableTransitions can be completely overwritten to
have the same transition (or set of transitions) assigned to all pages:
AvailableTransitions = [Crossfade]
Another use of info scripts is overriding the default or
command-line settings on a per-file basis. This can be done by simply
overwriting one of the variables that are defined at the beginning of
impressive.py. Each of these variables corresponds either to a
command-line setting, or to some constant related to visual appearance or
performance. So, for example, to force fullscreen mode for a presentation,
write
Fullscreen = True
The working directory while executing the info scripts themselves
is always the directory in which the info script is stored in.
The base directory for external actions that originate from Page
Properties or PDF hyperlinks is always the directory of the PDF or image
file this page belongs to. In other words, if e.g. 'sound':
"music.mp3" is written in the info script for one page of
presentation.pdf, the file music.mp3 is expected to be located
in the same directory as presentation.pdf.
Impressive and its documentation has been written mainly by Martin
J. Fiedler <martin.fiedler@gmx.net>, with small portions of the code
written by external contributors. See the source code file for details.
Report bugs to to <martin.fiedler@gmx.net>.