Archived from groups: rec.photo.digital (More info?
Ron Hardin <email@example.com> wrote:
>How do I get a .jpg to display at, say, double size?
>In Irfanview I can set the pixels but sometimes I get a big picture
>and sometimes I get a small one, mysteriously to me, for the
>same .jpg size.
>This pic http://home.att.net/
~rhhardin/bike.jpg is 640x496 and
>good-sized but only 87kb
>vs this almost identical one
~rhhardin/bikebackup.jpg which is 532x459 and
>about the same display size but 217 kb
>If I reduce the latter to half size (to get about the same kb) how
>can I get it to display double that size, at the current size?
>I like say 80kb pics, but am not sure how to get them all about
>600x600 display size.
>Firefox and/or Netscape browsers.
I assume those sizes are the file sizes stored on your
It turns out that all jpegs are "compressed". The degree
of compression depends on the amount of detail in the image.
Thus two TIFF images originally the same size (in pixels) will
produce different jpeg image sizes on disk.
For any single given TIFF file the higher the compression
the smaller the resultant file on the disk.
When you display the resulting files, the one with the
higher compression (smaller disk file size) will have less
detail and be more blocky.
There ain't no such thing as a free lunch.
Also, shrinking the actual size of the image prior to
turning it into a jpeg will decrease the size of the
But when you display that smaller image that's what you
will get, a smaller image. Again, TANSTASFL.
---- Paul J. Gans