GIF vs JPEG

This page was made to try to solve a discussion on news:comp.infosystems.www.authoring.html and comp.infosystems.www.authoring.images.

Ken Bigelow claimed that an image in JPEG-format would have a smaller filesize when saved as a GIF. Below is a quote from Ken:

I was speaking specifically about image file size, and more explicitly so elsewhere on this NG. Taking a 24-bit, 16M-color JPEG and reducing it to either an 8-bit, 256-color or 4-bit, 16-color GIF *will reduce the file size significantly.* I am fully aware that the JPEG compression method is more efficient than the GIF approach; they serve different purposes. But the use of lower-resolution GIFs, whether full-size or as thumbnails, is a common practice to allow access to the full picture but still allow faster loading.

I disagreed on that and proposed a challenge. Below here is some images in different formats. It's a picture of me (so I should be allowed to do anything I want with it).

Ken and I ended the argument in a civilized manner. He agreed that the JPEG-format is better than the GIF-format at making previews, provided that the original image is suitable for the JPEG-format.

Feel free to try to convert this image into GIF-format and send it to me (uuencoding preferred, base64 accepted). I'll put any images send to me on this page so it will be possible to compare the different filesizes to each other.

Bear in mind, that I'm not saying that JPEG is superior to GIF in all cases, just when it comes to photographs and such (see the JPEG-FAQ for more details).

Original image: 24bit TIFF scanned on mac.

The results so far:

Converter  Format     Size/bytes
Toke       TIFF           174019
Toke       JPEG 75%         6845
Toke       GIF 175         35492
Toke       GIF 16          17137
Ken        GIF 215         22853
Ken        GIF 16           7493
Toke       JPEG 25%         3555

My comments:
Ken did indeed produce a small GIF-version. Smaller than I'd have thought possible. However, that only made me produce an even smaller JPEG (with very visible quality-loss). So the question is: was that fair?

I've put Ken's best GIF and my best JPEG next to each other at the bottom of this page together with mine and Ken's "worst" (quality speaking), so that any readers can compare them more directly.
This, offcourse, requires a browser showing images...

Converter: Toke Eskildsen using graphicsconverter on mac.
Format:    JPEG 75%
Size:      304x214
Colors:    Hard to say
Filesize:  6845 bytes

Converter: Toke Eskildsen using graphicsconverter on mac.
Format:    GIF
Size:      304x214
Colors:    175
Filesize:  35492 bytes
Comment:   I don't know why graphicconverter didn't use 256 colors

Converter: Toke Eskildsen using graphicsconverter on mac.
Format:    GIF
Size:      304x214
Colors:    16
Filesize:  17137 bytes
Comment:   The image dithered, so it's not absolutely fair.
           Somebody care to produce a non-dither version?

Converter: Ken Bigelow using Paint Shop Pro 3.11.
Format:    GIF
Size:      304x214
Colors:    215
Filesize:  22853 bytes

Converter: Ken Bigelow using Paint Shop Pro 3.11.
Format:    GIF
Size:      304x214
Colors:    16
Filesize:  7493 bytes

Converter: Toke Eskildsen using xv on SGI.
Format:    JPEG 25%
Size:      304x214
Colors:    Hard to tell.
Filesize:  3555 bytes
Comment:   Since Ken's result from dithering to 4 bit resulted in a 
           very small file, which IMHO don't look that good, I tried 
           to turn down the quality on the JPEG, to achieve a similar 
           qualityloss/filesize tradeoff.

The first image is my JPEG at 75% (6845 bytes), the second is Ken's GIF in 215 colors (22853 bytes).

The third image is my JPEG at 25% (3555 bytes), the fourth is Ken's GIF in 16 colors (7493 bytes).

Maintained by Toke Eskildsen (darkwing@daimi.au.dk), Last changed 28 nov 96