>My name is Derek Mortimer.

>I am looking for an open source application to reduce the number of pixels, 
>thus reducing the number of kilobytes or megabytes, in a normal picture file, 
>jpeg, etc.

>In Photoshop, the process is called downsampling.  I have looked at the 
>documentation for GIMP and sampling does not seem to be the correct term for 
>the requisite process.  Nor can I find what is the correct term in GIMP.

>Does the process of pixel reduction and file size reduction exist in GIMP, 

>If it does, what is the technical term, please, so that I can look it up in 
>the documentation for GIMP?

>Thank you for your help.

>All the best,

>Derek Mortimer

You would think that PS 'downscaling' is the same as Gimp rescale but I have 
seen one PS article that rambled on about having a set of 'downscaled' images 
for setting up a DP printed page. Once the page is set up the full size images 
were substituted, why work this way I don't know, possibly commercial printers 
prefer this.

So my take on the subject adds one step to resizing an image.
say original jpg image is 1500x1500 pix (file size 440 KB) resized to 500x500 
pix (77 KB) if the print resolution (menu: Image -> Print Size) is set 
respectively to 300 & 100 then normally, with gimp default settings, the size 
difference is obvious. Turn off dot-for-dot (menu: view -> dot-for-dot) and the 
two images display the same.

screen shots. http://i.imgur.com/jhd16.jpg

Best algorithm for regular resizing, some say, bicubic, some sinc, it is a 
matter of preference.

Best compressed format for saving, obviously jpeg is lossy but it is universal 
and if it is the final image, why not.

rich (via gimpusers.com)
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