grayscale and resolution

[Anon]

Is there a way, using the PHP images functions to change a color image into a grayscale image, also is there a wat to determine and or change the resolution of an image?

[[deleted]]

Images don't have resolutions, images just have pixels. The resolution is just how many pixels you print per inch. Only 'professional' formats like Adobe's PSD contain resolution information so you can reproduce the image the way it's creator wanted it to be.

[[deleted]]

As for the grayscaling, use the GD library:

http://www.hvt-automation.nl/yapf/faq.php?cmd=viewitem&itemid=100

[tasistro]

Use mogrify from ImageMagick

$command="mogrify -verbose background\ DodgeThis.jpg"

$output=$command;

$output will hold the info as in the following command line
background DodgeThis.jpg 1024x768 DirectClass 70kb JPEG 0.2u 0:01
background DodgeThis.jpg=>bmagiccoiTRt 1024x768 DirectClass 70kb JPEG 1.0u 0:04

You can then parse any info you want

actual output from shell
[tazman@localhost tazman]$ mogrify -verbose background\ DodgeThis.jpg
background DodgeThis.jpg 1024x768 DirectClass 70kb JPEG 0.2u 0:01
background DodgeThis.jpg=>bmagiccoiTRt 1024x768 DirectClass 70kb JPEG 1.0u 0:04
[tazman@localhost tazman]$

BTW there is also convert. Check out their man pages. I like convert more as it has more features. You can use it to convert to grayscale and B&W.

Saludos
Gerardo