Thread
2005.05.02 14:16 "Re: [Tiff] Color TIFF/JPEG compression questions", by Joris
then the
points I made.> TiffTechNote 2 requires that if the underlying JPEG compression > uses YCbCr
Note that Photoshop apparently is able to save CMYK jpeg-in-tiff.
Tagdump of one such image generated with Photoshop:
SubFileType (1 Long): Zero
ImageWidth (1 Short): 3050
ImageLength (1 Short): 2035
BitsPerSample (4 Short): 8, 8, 8, 8
Compression (1 Short): JPEG Technote #2
Photometric (1 Short): SeperatedStripOffsets (407 Long): 26480, 50636, 74784, 99608, 124780, 150312,... SamplesPerPixel (1 Short): 4
RowsPerStrip (1 Short): 5
StripByteCounts (407 Long): 24156, 24148, 24823, 25172, 25532, 25662,... XResolution (1 Rational): 305
YResolution (1 Rational): 305
PlanarConfig (1 Short): Contig
ResolutionUnit (1 Short): Inch
Software (20 ASCII): Adobe Photoshop 7.0
DateTime (20 ASCII): 2004:08:29 15:13:38
DotRange (2 Byte): 0, 255
JpegTables (285 Undefined):700 (4649 Byte): 60, 63, 120, 112, 97, 99, 107, 101, 116, 32,... Photoshop (17958 Byte): 56, 66, 73, 77, 4, 37, 0, 0, 0, 0, 0, 16, 0,... 34665 (1 Long): 10661832
Upon examination of the first strip data, I see an APP14 marker, and 4 channels
specified in both the SOF0 and SOS marker. The 'color transform' byte in the
Adobe-style APP14 marker equals 0, which I take to mean that actual true CMYK is
encoded in the jpeg data, without additional tranformation.
Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html