ACDsee oddity

[Philip Colmer]

I'm using ACDsee to do a batch resize on some screenshots I've done for a review. The original files are a variety of sizes and I want to make sure that the images I use all conform to given limits.

So I point ACDsee at the original images, tell it to resize in pixels, specify the height & width I want, tell it to resize only (smaller images are acceptable), to preserve the original aspect ratio and to fit within width & height.

The process works but ... and here comes the weird bit ... the resized images often have a bigger filesize that the originals :!:

For example, an original image I've got is 546 x 401 and occupies 14KB. The ACDsee version is 350 x 257 and occupies 22KB :?

I just don't get it. I can't see any options that I can take advantage of.

Oh, these are GIF files.

--Philip

[Lee Yuan Sheng]

Probably a difference in the GIF compression. From 16 colours to 256 colours, different colour matching system, etc.

[Jason Dunn]

Yeah, what yslee said is probably accurate - check the number of colours in the GIF image and you'll probably find that there are more in the smaller version. ACDSEE may also be using a different palette (selection of colours), which can also impact the file size.

Unfortunately, GIF images resize very poorly - hindsight is 20/20 of course, but it's best to take screenshots as BMP files, then resize them and convert to GIF as the final stage.

[Philip Colmer]

Unfortunately, GIF images resize very poorly - hindsight is 20/20 of course, but it's best to take screenshots as BMP files, then resize them and convert to GIF as the final stage.
Next time :D

--Philip

[Janak Parekh]

Unfortunately, GIF images resize very poorly
Why? GIF's non-lossy, right? Is it due to the fact that GIFs are max 8-bit images?

FWIW, I use PNGs as my source material. As good as BMP, but much better compression. ;)

--janak

[Jason Dunn]

Why? GIF's non-lossy, right? Is it due to the fact that GIFs are max 8-bit images?

Correct - 8 bits isn't much data, and the results are horrific. Lines shear badly...just bad all around.