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| author | no_author <no_author@no_author> | 2005-11-08 17:40:41 +0000 |
|---|---|---|
| committer | no_author <no_author@no_author> | 2005-11-08 17:40:41 +0000 |
| commit | 220a21bd01a1fcec4f39a005c496d24f85bbd0dd (patch) | |
| tree | 9969dbf3c0fba0f9c576dbef6bae2336e4a854ad /codec/readme.txt | |
| parent | 34a4901b8deedafa18fa433d2b5fe311343457d8 (diff) | |
This commit was manufactured by cvs2svn to create tag 'start'.start
Diffstat (limited to 'codec/readme.txt')
| -rw-r--r-- | codec/readme.txt | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/codec/readme.txt b/codec/readme.txt new file mode 100644 index 00000000..972fac4e --- /dev/null +++ b/codec/readme.txt @@ -0,0 +1,105 @@ +List of parameters for the coder JPEG 2000 : + +Date : June the 25th, 2003 +Author : Yannick Verschueren +Contact : verschueren@tele.ucl.ac.be + +- the option -help displays the readme.txt file on screen + +- The markers COD and QCD are writed both of two in the main_header and never appear in the tile_header. The markers in the main header are : SOC SIZ COD QCD COM. + +- This coder can encode mega image, a test was made on a 24000x24000 pixels color image. You need enough disk space memory (twice the original) to encode the image. (i.e. for a 1.5 Gb image you need a minimum of 3Gb of disk memory) + +REMARKS : +--------- + +* the value of rate enter in the code line is the compression factor ! +exemple : + +-r 20,10,1 means quality 1 : compress 20x, quality 2 : compress 10x and quality 3 : compress 1x = lossless + +* The number of resolution can be modified by the program in view to respect profile-0 conditions (Taubman, Marcelin (2002), "JPEG2000, image compression fundamentals, standards and practice", p700) + +By default : +------------ + + * lossless + * 1 tile + * size of precinct 2^15 x 2^15 (means 1 precinct) + * size of code-block 64 x 64 + * Number of resolution : 6 + * No SOP marker in the codestream + * No EPH marker in the codestream + * No sub-sampling in x and y direction + * No mode switch activated + * progression order : LRCP + * No index file + * No ROI upshifted + * No offset of the origin of the image + * No offset of the origin of the tiles + * Reversible DWT 5-3 + +Parameters : +------------ + +-i : source file (-i source.pnm also *.pgm, *.ppm) "required" + +-o : destination file (-o dest.j2k) "required" + +-r : different rates (-r 20,10,5) "optional" + +-n : Number of resolution (-n 3) "optional" + +-b : size of code block (-b 32,32) "optional" + +-c : size of precinct (-c 128,128) "optional" + +-t : size of tile (-t 512,512) "optional" + +-p : progression order (-p LRCP) [LRCP, RLCP, RPCL, PCRL, CPRL] "optional" + +-s : subsampling factor (-s 2,2) [-s X,Y] "optional" + +-SOP : write SOP marker before each packet "optional" + +-EPH : write EPH marker after each header packet "optional" + +-M : mode switch (-M 3) [1= BYPASS(LAZY) 2=RESET 4=RESTART(TERMALL) 8=VSC 16=ERTERM(SEGTERM) 32=SEGMARK(SEGSYM)] "optional" + for several mode switch you have to add the value of each mode you want + ex : RESTART(4) + RESET(2) + SEGMARK(32) = -M 38 + +-x : Create an index file *.Idx (-x index_name.Idx) "optional" + +-ROI:c=%d,U=%d : quantization indices upshifted for component c=%d [%d = 0,1,2] + with a value of U=%d [0 <= %d <= 37] (i.e. -ROI:c=0,U=25) "optional" + +-d : offset of the origin of the image (-d 150,300) "optional" + +-T : offset of the origin of the tiles (-T 100,75) "optional" + +-I : Use the irreversible DWT 9-7 (-I) "optional" + +IMPORTANT : +----------- + +* subsampling bigger than 2 can produce error + +The index file respect the structure below : +--------------------------------------------- + +Image_height Image_width +progression order +Tiles_size_X Tiles_size_Y +Components_nb +Layers_nb +decomposition_levels +Precincts_size_X Precincts_size_Y +Main_header_end_position +Codestream_size +Tile0 start_pos end_Theader end_pos +Tile1 " " " +... +TileN " " " +Tpacket_0 Tile layer res. comp. prec. start_pos end_pos +... +Tpacket_M " " " " " " " |
