RAW files from the -D and the -DS are *NOT* compressed, losslessly or otherwise. They are only "compressed" for the -DS in that they put 12-bits of data into 12-bits, rather than putting 12-bits into 16-bits and wasting 4 with zeros. If you figure out 3040x2024x12 = 73.8Mbits = 9229440 = 8.8x2^20 (i.e. MB). The output of 'tiffinfo' says:He also says that RAW does not compress losslessly. I knew this was the case for the -D but thought itwas fixed for the -Ds. Am I wrong as usual/expected?
Interesting that RAW is a compressed file. At 12mb or so, it had damned well better be lossless.
I suppose the question begged is how do you know this?
Did you read it on the net?
William Robb
tiffinfo -s test.pef
test.pef: Warning, unknown field with tag 34665 (0x8769) ignored.
TIFF Directory at offset 0x8
Image Width: 3040 Image Length: 2024
Resolution: 72, 72 pixels/inch
Bits/Sample: 12
Compression Scheme: PackBits
Photometric Interpretation: 32803 (0x8023)
Date & Time: "2005:03:31 09:47:32"
Software: "*ist DS Ver 1.01 "
Make: "PENTAX Corporation "
Model: "PENTAX *ist DS "
Orientation: row 0 top, col 0 lhs
Samples/Pixel: 1
Rows/Strip: 2024
Planar Configuration: single image plane
1 Strips:
0: [ 73728, 9229440]
test.pef: Warning, unknown field with tag 513 (0x201) ignored.
test.pef: Warning, unknown field with tag 514 (0x202) ignored.
test.pef: TIFF directory is missing required "ImageLength" field.Notice the lines:
1 Strips:
0: [ 73728, 9229440]
That's the RAW image... offset 73728 in the file, of size 9229440 bytes.The rest of the crud in there are the multiple JPEGs, EXIF info, etc. Basically exactly 8.8MB of the RAW file are used for the RAW image.
If someone sent me a *ist-D RAW file, I'll poke around through that, too and verify that it's 12-bits padded to 16.
-Cory
************************************************************************* * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * *************************************************************************
