Most space-efficient format for image with large dimensions but few colors?

1

Recently I have had to scale up the dimensions of a gif image by a factor of 2, this resulted in an increase of the file size by about 8 times. While this is not a complete surprise, I can't help but think there should be a format that scales well with such an operation.

prusswan

Posted 2012-11-14T18:59:02.943

Reputation: 328

Can the image be remade as a Vector image or are you stuck as Raster?

– Scott Chamberlain – 2012-11-14T19:23:21.160

@ScottChamberlain actually you brought up a good point, except that what I had in mind was something to be used with google maps – prusswan – 2012-11-14T19:36:08.170

Google maps stores it's data as tiles, then does small shrink (never expand) as you zoom out. Once you have zoomed out enough it sends a new image at the same resolution as the old one but at a different scale. – Scott Chamberlain – 2012-11-14T20:37:09.283

Answers

1

Compression in GIF images is quite primitive and cannot take advantage of redundancy created by upscaling of the image.

I you resize without anti-aliasing then well-optimized PNG shouldn't grow by much.

If you resize with anti-aliasing then convert the image to JPEG, as this will create lots of new colors and soft edges that are best handled by JPEG.

Kornel

Posted 2012-11-14T18:59:02.943

Reputation: 1 225