Resizing Certain Pictures Turns Them Blue

[tundra]

This has to be a strangest things I've seen yet, and it's probably not a PHP error, but here it goes anyway.

I have a thumbnail creator that uses GD (no other choice here, so no imagemagick), that works fine, except in rare cases (and I have to emphasize that, for 90% of all other converted images, nothing unusual happens), they become tinted in blue once they're resized.

I figure it has to be the images because the event only happens to those particular images; however I have tried a number of image modifications (including copying the image and pasting it to a new image, changing the brightness and contrast, and what not) and yet, the strange tint persist.

If you need to see the code, I'd be glad to post it, but I don't think that's where the problem lies as, like I said before, most images come out fine.

If anyone else has ever seen anything like this and knows what can be done to fix this error, I'd love to hear it.

TIA

[djroki]

This sounds like something the developers of GD might like to hear about (or might know of the cause).

If you've read the manual (especially the known issues section), maybe try a polite email to them.

Their homepage is here:

http://www.boutell.com/gd/

good luck, roki

[tundra]

I found out what it is, and I figure whoever uses GD for image manipulation might want to know this.

If you use ImageCreate() to initialize an image, that image can only contain 256 colors.

If you need an image to use more colors than that, use ImageCreateTrueColor(), and that will create an image that can use an unlimited amount of colors.

[tundra]

Subsequently, I've also discovered that imagecreatetruecolor() only exist in GD 2+

[tundra]

In addition to all of this, I've also discovered that, with versions of GD that are < version 2.0, this appears to be a moot point.