Written 'for Dummies', written by 'Complete Idiots'?

[lovingboth]

Saved until the geeks got back... from Fireworks 4 for Dummies

"[JPEG] is also a lossy format, which means the image can be compressed. When an image is compressed [in any way] certain information is lost."

Comments

Buh?

[kingginger.livejournal.com]

Whats wrong with that?

Re: Buh?

[ciphergoth.livejournal.com]

There is such a thing as "lossless compression". For a simple example, consider a fax, in which every pixel is either black or white. Faxes are compressed losslessly by encoding the length of runs of black and runs of white, rather than encoding each pixel individually. If the entire fax were random, like the snow on an untuned TV, this wouldn't work, but real faxes contain large white areas and smaller but still significant black areas, so encoding run lengths is more efficient.

Re: Buh?

[lovingboth]

Indeed, particularly as they've just introduced .gif and .png

Re: Buh?

[ciphergoth.livejournal.com]

I think of GIF as lossy since you have to convert to a 256-colour pallette to use it. But PNG offers 24-bit lossless compression.

Re: Buh?

[djm4]

I think of GIF as lossy since you have to convert to a 256-colour pallette

...says the chap who just used black and white faxes as an example of lossless compression.

Re: Buh?

[lovingboth]

I don't, but then I wouldn't use it for something that needed more than 256 colours.

One day, Acrobat will support .png ...