Issues with Scanner/Resolutions

[blahsum]

Hi guys

I have a problem: images I save are huge. As in a GIF file of a line-art piece (approx 600pixels across, A4) weighs in at 300KB or more.

This doesn't happen with low-res art I open from elsewhere. It's specific to stuff I scan (using a Canoscan LIDE 100 via the scanner driver, not Paint.net's own scanner dialog). The files are saved externally at 300DPI, then brought into Paint.NET. Here I make whatever changes - including a drop of the pixel res by 25%, dropping DPI to 100 and converting the file to black and white.

Yet I get these massive file sizes in Gif, JPG or PNG. An uncompressed JPG goes to 500KB! It makes no sense to me, but it is consistent with a file that registers as 300dpi. but the file is reduced - it reports as and scales to the visual sizes consistent wit the downgrades.

This is a serious problem - I can't use Paint.net if my file sizes have suddenly doubled! So any advice or insight would be great.

for example, is it possible to access the scanner driver interface via Paint.net? Maybe that can make a difference.

thanks,

James

[Rick Brewster]

This may help:

http://forums.getpaint.net/index.php?/topic/17049-dpi-and-you-understanding-resolution-for-print-and-web/

tl;dr: DPI only matters when printing, and is strictly a number used to calculate the physical size of the image. If you want to reduce the file size, then change the pixel size and/or quality (when saving as JPEG).