How to create thumbnail that is only part of original one?

[kenle]

Hi,

What I want to do is to create a thumbnail image that focus only the first half part of the original images.

So for example, if i have a portrait picture uploaded, i want a thumnail of that picture is created, but instead of a smaller version of that picture, it should only show the face of that portrait.

Anyone here have an idea how to do it?

Thanks

[weekender]

you can use the [man]image[/man] functions to crop an image (ie display a certain part), but to display the face you would either have to do it manually or have some kind of image recognition to detect which part of the image is the face - and i'm not going anywhere near that!

if you wanted to do it manually, i know there is something about having an image as a submit image in a form, and when you click it it submits the x and y variables showing where on the image you clicked. To crop an image, you just need top-left and bottom-right co-ordinates - if you uploaded an image, clicked top left, stored the click, clicked bottom left, you would be able to crop the image based on those co-ords and use image functions to do the crop

adam

[kenle]

Look like the function to crop the images the way I want is imagecopyresized()

Suppose, all my images upload all have a certain size, like 300 x 400 pixels for example. And for instance, I want the thumbnail to have the first half of the image. Should I call this function like this?:

imagecopyresized(dest, src, 0,0,0,0,300,200,srcW,srcH)

[weekender]

sounds good, though i'm a bit rusty with it to be honest

also, php with versions of GD (the graphics module) greater than 2.0.1 have a function [man]imagecopyresampled[/man] which does exactly the same as [man]imagecopyresized[/man] and works the same, but resamples the images - meaning clearer thumbnails at better quality (although marginally slower)