GD function

[mhalloran]

I've never used the GD library in PHP and I'm struggling to do what should be a simple task. I want to turn color thumbnails into grayscale thumbnails. I need to do this with both GIF and JPG images. I managed to enable GIF create support on my server and I'm assuming that I can create a JPG image as well. Here are the GD details:

GD Support enabled

GD Version 2.0 or higher

FreeType Support enabled

FreeType Linkage with freetype

GIF Read Support enabled

GIF Create Support enabled

JPG Support enabled

PNG Support enabled

WBMP Support enabled

So what's the function for doing this? The user will upload a color thumbnail and I want to first save that thumbnail (for which I've already written the script) and then save the thumb again in gray-scale. I'm doing this so that the black and white images will turn colored when you hover over them. For each image uploaded I want two saved on my server like this:

image1.jpg
image1_bw.jpg

Any ideas?

[Sphynx]

I've never used it personally, but it looks like imageCopyMergeGray() should do the trick.

http://de3.php.net/manual/en/function.imagecopymergegray.php

[Weedpacket]

I haven't used it either, but from the cited page I guess you could use the image that is supposed to be greyed out as the "destination", and use a percentage of 0.

[mhalloran]

Perfect.

I'll look into that function and post my results.

Cheers

[Mordecai]

I've written a script that might be of use to you. It's called the Leonardo Image Functions Library, and it has some basic commands such as imagegrayscale, which turns an image into its grayscale equivalent.