2009.12.10 18:28 "[Tiff] YCbCr", by Steve Mills

2009.12.10 22:31 "Re: [Tiff] YCbCr", by Steve Mills

I used the dump function to see what the differences between the jpeg-compressed cmyk files might be. Here's the output for the file saved in Photoshop CS3, the one that produces incorrect results:

TIFFSetField: dummy: Unknown pseudo-tag 65538.

Magic: 0x4d4d <big-endian> Version: 0x2a
Directory 0: offset 8 (0x8) next 0 (0)
SubFileType (254) LONG (4) 1<0>
ImageWidth (256) SHORT (3) 1<4>
ImageLength (257) SHORT (3) 1<4>
BitsPerSample (258) SHORT (3) 4<8 8 8 8>
Compression (259) SHORT (3) 1<7>
Photometric (262) SHORT (3) 1<5>
StripOffsets (273) LONG (4) 1<25360>
Orientation (274) SHORT (3) 1<1>
SamplesPerPixel (277) SHORT (3) 1<4>
RowsPerStrip (278) SHORT (3) 1<4>
StripByteCounts (279) LONG (4) 1<128>
XResolution (282) RATIONAL (5) 1<72>
YResolution (283) RATIONAL (5) 1<72>
PlanarConfig (284) SHORT (3) 1<1>
ResolutionUnit (296) SHORT (3) 1<2>
Software (305) ASCII (2) 30<Adobe Photoshop CS3 Maci ...>
DateTime (306) ASCII (2) 20<2009:12:10 15:08:12\0>

JPEGTables (347) UNDEFINED (7) 558<0xff 0xd8 0xff 0xdb 00 0x84 00 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x3 0x2 0x2 0x2 0x3 0x4 0x3 ...>

700 (0x2bc) BYTE (1) 15890<0x3c 0x3f 0x78 0x70 0x61 0x63 0x6b 0x65 0x74 0x20 0x62 0x65 0x67 0x69 0x6e 0x3d 0x22 0xef 0xbb 0xbf 0x22 0x20 0x69 0x64 ...>

33723 (0x83bb) LONG (4) 2<469893120 33554432>
34377 (0x8649) BYTE (1) 8552<0x38 0x42 0x49 0x4d 0x4 0x4 00 00 00 00 00 0x7 0x1c 0x2 00 00 0x2 00 00 00 0x38 0x42 0x49 0x4d ...>
34665 (0x8769) LONG (4) 1<25488>

And here's the file from CS4, which produces correct results:

TIFFSetField: dummy: Unknown pseudo-tag 65538.

Magic: 0x4d4d <big-endian> Version: 0x2a
Directory 0: offset 8 (0x8) next 0 (0)
SubFileType (254) LONG (4) 1<0>
ImageWidth (256) SHORT (3) 1<4>
ImageLength (257) SHORT (3) 1<4>
BitsPerSample (258) SHORT (3) 4<8 8 8 8>
Compression (259) SHORT (3) 1<7>
Photometric (262) SHORT (3) 1<5>
StripOffsets (273) LONG (4) 1<18814>
Orientation (274) SHORT (3) 1<1>
SamplesPerPixel (277) SHORT (3) 1<4>
RowsPerStrip (278) SHORT (3) 1<4>
StripByteCounts (279) LONG (4) 1<117>
XResolution (282) RATIONAL (5) 1<72>
YResolution (283) RATIONAL (5) 1<72>
PlanarConfig (284) SHORT (3) 1<1>
ResolutionUnit (296) SHORT (3) 1<2>
Software (305) ASCII (2) 30<Adobe Photoshop CS4 Maci ...>
DateTime (306) ASCII (2) 20<2009:12:10 14:35:21\0>

JPEGTables (347) UNDEFINED (7) 285<0xff 0xd8 0xff 0xdb 00 0x43 00 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x2 0x3 0x2 0x2 0x2 0x3 0x4 0x3 ...>

700 (0x2bc) BYTE (1) 15863<0x3c 0x3f 0x78 0x70 0x61 0x63 0x6b 0x65 0x74 0x20 0x62 0x65 0x67 0x69 0x6e 0x3d 0x22 0xef 0xbb 0xbf 0x22 0x20 0x69 0x64 ...>

34377 (0x8649) BYTE (1) 2324<0x38 0x42 0x49 0x4d 0x4 0x25 00 00 00 00 00 0x10 00 00 00 00 00 00 00 00 00 00 00 00 ...>
34665 (0x8769) LONG (4) 1<18932>

The StripOffsets and StripByteCounts are different, as are the JPEGTables. I certainly don't understand any of that, but shouldn't we expect the same row data for each row read?

_________________________________________________________
Steve Mills Me: 952-401-6255
Senior Software Architect MultiAd
smills@multiad.com www.multi-ad.com