Oh yeah, I love transparent bitmaps!! Really.
And hey, what dumbasses, if they converted their gifs into bitmaps they would be bettering the quality. Yeah, crappy GIF format....
j/k
GIF is a very good format for little images for the web. It is limited to 256 colors, but sometimes you don't even need more than 10 colors to have a proper image.
My winamp tracker has 200 colors (it's png, but it's similar in this case) Do you think it's crappy? I could export it in same (or better if I get it to 256 colors) quality to GIF and you wouldn't notice any crappy color transition. At least without zooming in.
GIF files don't need to have data for colors they don't even contain (<- If you got this sentence you're a genius
)
look at my example:
All images are 100x100pixels.
First image:
I grab my Photoshop and do that color mixture. It doesn't have all colors but you'll agree that it has a wide range, at least more than 256 colors (if you ever had an old VGA-card you'll notice that those are way more than 256 colors
). Well. I exported it into BMP24bit (this BMP uses 24 bits = 3 bytes to define the color of one pixel). That means 30.000 bytes. Those 56 bytes are due to formatting and color data (somewhere the picture needs to have information about the dimensions, and the color, f.i.
)
Second image:
That is the maximal quality I can get with GIF upon this image. If you compare 1 and 2, you'll see that the second image has a slight quality loss. But you wouldn't have noticed if they weren't put together. (Don't get so close to the screen!
) Why? Well, yeah... it's 8 bit color, 1 byte per pixel. Calculator: 1 * 100 * 100 = 10.000.
However image number 2 is less than 7.5KiB big. Houston, we've got a problem. Don't worry. GIF uses a technology that makes it capable to index certain colors that are repeated and makes pixels with that color smaller in size. There are not many repeated colors in this image, but there are. So the advantage of GIF is set in by the compressor. You can compare it to:
Third Image:
This is a copy of image 2 in BMP with 24 bit color. A real waste of space, since only 256 colors are used. This is what you are happy to do, Millenium_edition.
all pixels are capable to show 24bit colors, but they effectively only show 256, and hence it's 300% size (8bit to 24bit).
BMP24, btw, it the standard BMP format nowadays.
Fourth Image:
BMP 8bit. Yeah, that would be the alternative to the big fat 24bit BMP. And should be enough to show our low quality image. Remember that it's a copy of image 2, it haz only 256 colors anyway, so BMP8 fits it perfectly. But no luck. That color indexing of GIF does no longer exist in here
.
And even more. It got magically about 1KiB more than expected (1*100*100 = 10.000). I'm not sure about this, but maybe, some colors in the image are not in the standard 256 colors of BMP8 (if you ever had an old VGA you'll get what I mean, again
). Those base 256 colors are fixed colors, but we are probably using a bunch of othe colors in here that don't fit to BMP8 standard colors. Paint exported real crap in BMP8. Photoshop was a bit kinder and exported it in BMP8, but corrected old colors to fit the real colors with only 1KiB more.