Image Formats

Giganews Newsgroups
Subject: Image Formats
Posted by:  Joy Beeson (jbeeson@invalid.net.invalid)
Date: Thu, 20 Aug 2020

Background:  I put a back-up copy of a book I was writing in the space
my server allowed for a Web site, then I decided that I might as well
link to it, then I needed to use the word appliqué a lot and
started converting ASCII files to hypertext -- a job still in progress
-- then I started photographing some of the things I was talking about
and posting pictures between paragraphs.  (The pictures are cropped
and scaled to a uniform width of 600 pixels.)

I've been using JPG exclusively because that what I get out of my
camera.

Yesterday I wanted to photograph a letter-size piece of paper on which
I'd drawn a pattern, and realized that the right way was to scan it.

My scanner offers JPG, TIF, and PNG.  I made one scan in each format.

JPG:  35 389 KB
TIF:  98 666 KB
PNG:  77 107 KB

Then I tried to open the files in Firefox so that I could compare
them.  Firefox couldn't open the TIF file, so that ruled out using the
TIFF copy, which I was already dubious about because ninety-eight
thousand kilobytes is a lot of space.

Then I blinked back and forth between the JPG and the PNG and couldn't
see the slightest bit of difference, not on shrink to fit screen and
not on 100%.  (Which is *huge*; maybe I should reduce the resolution
of the scanner.

So what do I get for the extra thirty-seven thousand KB PNG costs, and
what is each of these formats good for?

-------------

I believe that in theory a line drawing takes up less space in GIF
than in JPG.  The scanner doesn't do GIF.

So I stopped here to load the JPG into GIMP and export it as GIF:

GIF:  26 182 KB

Again, my blink comparator shows no difference whatsoever between the
two images.

I'd already deleted the two rejected formats.

Would I get better results if I exported one of the other two formats
into GIF?  Enough better to re-scan the pattern?

--
joy beeson at centurylink dot net
http://wlweather.net/PAGESEW/
The above message is a Usenet post.

..

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