PNG Resizing for thumbnails results in larger filesize!

Aron_Schatz

Hey Everyone,

I know the problem, and I did a search on the board before I posted this and a search on the internet.

What happens is that when I want to make thumbnails of PNG/JPEGs, I have a function that just handles it for me using imagecreatetruecolor() for the output image. Now the problem is when the input PNG is (let's say) 400x300 and is in PNG-8 with only 4 colors, the output (at let's say 80x60) results in a PNG-24 image and the filesize is generally larger than the original image.

Is there anyway to tell if the input image is a paletted based image (PNG-8) so I can use imagecreate() in the function instead of making a true color image for nothing?

Anything else you can think of is great as well, Thanks in advance.

Aron_Schatz

Damn, okay... Well I figured to just use palette based images for all PNGs (given they are screenshots anyway).

imagecopyresampled($out, $tmp, 0, 0, 0, 0, $neww, $newh, $oldw, $oldh);

This does not work right, $out is the new images made from imagecreate(), and $tmp is the image made from imagecreatefrompng().

Since $out is a palette image and $tmp is a truecolor, it is just showing a black image all the time. How can I convert $tmp into a palette based image?