ojph_compress - This program reads in an image of a certain type
and converts it to a HTJ2K (JPH) file. It is part of the OpenJPH
library.
-i input file name (either pgm, ppm, tif(f), or
raw(yuv))
-o output file name
- -num_decomps
- (5) number of decompositions
- -qstep
- (0.00001...0.5) quantization step size for lossy compression; quantization
steps size for all subbands are derived from this value. {The default
value for 8bit images is 0.0039}
- -reversible
- (false) for irreversible; this should be false to perform lossy
compression using the 9/7 wavelet transform; or true to perform reversible
compression, where the 5/3 wavelet is employed with lossless
compression.
-colour_trans (true) this option employs a color
transform, to
- transform RGB color images into the YUV domain. This option should not be
used with YUV images, because they have already been transformed. If there
are three color components that are downsampled by the same amount then
the color transform can be true or false. This option is also available
when there are more than three colour components, where it is applied to
the first three colour components. it has already been applied to convert
the original RGB or whatever the original format to YUV.
- -prog_order
- (RPCL) is the progression order, and can be one of: LRCP, RLCP, RPCL,
PCRL, CPRL
- -block_size
- {x,y} (64,64) where x and y are the height and width of a codeblock. In
unix-like environment, { and } must be proceeded by a \
- -precincts
- {x,y},{x,y},...,{x,y} where {x,y} is the precinct size starting from the
coarest resolution; the last precinct is repeated for all finer
resolutions
- -tile_offset
- {x,y} tile offset.
- -tile_size
- {x,y} tile width and height.
-image_offset {x,y} image offset from origin.
- -profile
- (None) is the profile, the code will check if the selected options meet
the profile. Currently only BROADCAST and IMF are supported
When the input file is a YUV file, these arguments need to be
- supplied: -dims {x,y} x is image width, y is height
-num_comps number of components -signed a comma-separated
list of true or false parameters, one
- for each component; for example: true,false,false
-bit_depth a comma-separated list of bit depth values,
one per
- component; for example: 12,10,10
- -downsamp
- {x,y},{x,y},...,{x,y} a list of x,y points, one for each component; for
example {1,1},{2,2},{2,2}
This manual page was written by Mathieu Malaterre
<malat@debian.org> for the Debian GNU/Linux system (but may be used by
others).