2005.05.26 12:24 "Re[3]: [Tiff] How to Write a tif file with compression = COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant

I really misunderstood the word "comment" & "uncomment":(..., and thus brings me a lot of messy things...:((((-.

I did what you real said, and it works.(then what does that bug of TIFFWriteScanline()..means ???).

Hum..., you can try to fix the bug of TIFFScanlineSize, and test with some libtiff clients on various platforms...... :-)

with bitcount=24 image, i did like this..

but with grayscale image(bitcount= 8)

If you want the widest standard for your jpeg stream, compress as RGB/YCBCR 24 bits is better. Tiff allows a one component photometric minisblack ( with a unknown colorspace for jpeg stream ).

,(some may have palette,

If you mean "gray reponse curve", such a gamma, it's legal, but result might be very poor.

some may not [just like color image]) should i shift the grayscale image data to RGB mode?

Jpeg compression of palette color indexes would be as strange idea as jpeg compression of CIELAB. And it is out of spec.

Jean-Yves