PHP Functions - Imagecolorexactalpha, TrimImage() and TrimImage()

The php function imagecolorexactalpha allows you to scan through an image pixel by pixel performing some kind of action on each one, and then saving the new pixels to a new canvas. This is a great tool for retouching photographs and is amazingly fast (as long as your images are not too big).

This php function makes it easier to work with TGA images in your web applications. It does this by making the colors of the palette version of the image more closely match the color of the true color version. It also fixes a problem with the getimagesize function that is caused by not supporting TGA files.

php function imagecopyresampled

A lot of us use the src=image/jpeg, dst=image/png, and a div around it for image scaling in our websites. However, a lot of the time you want to scale an image and still retain a high level of clarity. This is when a function like the php function imagecopyresampled comes in handy.

php function trimImage()

The php function trimImage() returns the top-most, right-most, bottom-most and left-most position in an image for a given colour so that it is not trimmed off. This is useful if you want to save space on your website or if you are using an image as a background for a table or something similar.