Last week I got some 35mm negatives transferred onto a Kodak Photo-CD with 
the intention of being able to display them as the root window on an 
X-terminal. After a bit of experimenting, I have succeeded to my 
satisfaction. This is how I did it, for anyone that's interested. Please
excuse any duplication of information; I wasn't subscribed to the relevant 
groups earlier on.

Andrew Daviel, Vancouver BC

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After trying xv, xloadimage, ppmquant and ppmtogif, I found that 
cjpeg gives me the best results. The colour conversions of fleshtones on some 
portraits with xv 2.21 were noticeably bad; ppmquant was slightly better. The 
images in question had too many colours for ppmquant to translate using 256 
levels, so that it converted to 64 levels before histogramming.

The following commands worked for me on a Sun sparcstation with Sun CD-ROM 
drive running Openwindows:
 su
 mkdir /cdrom
 mount -rt hsfs /dev/sr0 /cdrom
 hpcdtoppm -4 /cdrom/photo_cd/images/img0001.pcd > tmp.ppm
 cjpeg -Q 95 tmp.ppm > img0001.jpg && rm tmp.ppm
 umount /cdrom

I have been told that this drive will only read the first session of 
the CD; so that if additional rolls are written to the photo-CD a 
multi-session drive would be needed.
Although I could make a full resolution jpeg file, I could not view it (xv 
ran out of memory on a 16Mb sparcstation). The full/4 is slightly larger than 
the screen and can be viewed using xv -nolimits, and then scaled or cropped
as desired. xv can be used to convert jpeg to GIF, Postscript, etc. I have 
ported a GIF file to cshow under DOS, after using xv to scale it to fit the 
800 x 600 format of the super-VGA display.

hpcdtoppm can extract 5 different resolution pictures from the pcd file. The
full resolution is 2048 by 3072 pixels in 24-bit colour. The pcd files are 
typically 4Mb. The extracted files typically take the following amount of
space: 

N	Pixels		PPM	GIF	JPG 90%
1	192 x 128	73k	23k	13k
2	384 x 256	294k	84k	?   )
3	768 x 512	1M	308k	?   )  - didn't try
4	1536 x 1024	4M	1M	340k
5	3072 x 2048	18M	-	2M	(too big for xv to read)


cjpeg from the JPEG software package; try archie
hpcdtoppm from wuarchive:/usenet/alt.sources/6541.Z
 (>From: danisch@ira.uka.de (Hadmut Danisch ))
 (>Subject: PhotoCD to PPM converter v0.2 Part 1/1)
ppmquant and ppmtogif from pbmplus; try archie