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[sindi keesan <keesan AT sdf.lonestar.org>]

Rather than upload megabytes of 200K 1280 res photos, I am using netpbm 
programs to cut the size to 50K.  pamscale reduces X and Y by the same 
factor as a default (.5 in my case).
I called my script halve.

jpegtopnm $1 > temp1.pnm
pamscale .5 temp1.pnm > temp2.pnm (or big.pnm and small.pnm if you prefer)
pnmtojpeg temp2.pnm > temp.jpg

Halve photo1.jpg  produces temp.jpg  but I want to get back a photo1.jpg 
that is the same but 1/4 the size.

I have to rename temp.jpg back to the original file name individually.

I have tried various changes to my script and they all produce 0 length 
files.  I don't think I can output > $1 to end up with the same name file 
I started with.

How can I at least avoid the step of renaming temp.jpg, and if possible, 
how can I shrink all the files in a directory with one command or script?

For i in .... ?

No I don't want to use gimp or get broadband.  People without broadband 
will be downloading the images and gimp is X so slower.

The tools are netpbm and BL3 busybox in BL2.

I bet there are several ways to do this.

Pamscale is taking 5-10 seconds per photo and uses 99.8% of cpu but very 
little memory to scale down (reduce).  It must be averaging out the colors 
of two pixels to make one.  Scaling up takes much longer.  500MHz.
Don't try this on a 486.  Rotating images takes more memory and crashes a 
486 with 24MB RAM and no swap file.

I also used netpbm to combine four 1/4 size pdf pages of the camera manual 
into one pbm page that I could print (I did this all manually) and next 
time I will read the manual and make smaller files to start with.
The camera is a year newer than the computer.

keesan AT sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org