Reducing the size of an image

[kjc]

Hi,

Does anyone know if PHP can compress an image. I have a site where by users can upload images of themselves to be displayed in their profile. But I want to know if it is possible to compress it. Ie if they upload a 400kb photo, can I reduce this at all?

Kjc

[whofarted]

you could use GD or image magick & make it thumbnail all images over a certain size.

That would help make sure all images are say...less than 500x500 so they don't cause huge pictures to need scroll bars & file size (weight) would be reduced at the same time.

[Mincer]

Using the image functions, you can resize, crop, and otherwise manipulate the image. You can also pass a second paramater to imagejpeg() to specify the jpeg compression quality (if you want to use jpegs).

Regards,

Matt.

[peanuts]

Hi,

Does anyone know if PHP can compress an image. I have a site where by users can upload images of themselves to be displayed in their profile. But I want to know if it is possible to compress it. Ie if they upload a 400kb photo, can I reduce this at all?

Kjc

This is part of a script that I found here [img]images/smilies/smile.gif[/img]

function resize($image, $thumb, $x, $y, $type) {
$rat = 150;  // the max length (or width)
$success = 0;
if($type == "jpg" ) {
$src = ImageCreateFromJpeg($image);
}
elseif($type == "gif" ) {
$src = ImageCreateFromGif($image);
}
if ($x > $y) {
$imagey = ceil(($rat * $y) / $x);
$imagex = $rat;
}
if ($y > $x) {
$imagex = ceil(($rat * $x) / $y);
$imagey = $rat;
}
if ($y == $x) {
$imagex = $rat;
$imagey = $rat;
}
$dst_img=ImageCreateTrueColor($imagex,$imagey); 
ImageCopyResized($dst_img,$src,0,0,0,0,$imagex,$imagey,$x,$y);
if($type == "jpg" ) {
ImageJpeg($dst_img, $thumb);
$success = 1;
chmod($thumb, 0644);
}
elseif($type == "gif" ) {
ImageGif($dst_img, $thumb);
$success = 1;
}
return $success;
} 

I hope it helps [img]images/smilies/wink.gif[/img]

[siteguru]

Here is a thumbnail script I created ... you use it by simply passing the filepath and desired width to it in an <img> tag ... e.g. ...

<img src="thumbnail.php?src=/path/to/image.jpg&maxw=400" />

http://www.siteguru.co.uk/codes/thumbnail.txt

[alt-f4]

Peanuts, your fuunction would be useful to me, but I have a question. When I run the function on an image the exif data is lost. Is it possible to create the new images and keep the exif data?

[peanuts]

Peanuts, your fuunction would be useful to me, but I have a question. When I run the function on an image the exif data is lost. Is it possible to create the new images and keep the exif data?

Sure you just have to point the exif function to the correct path (even if it's a temp path..) or just fill a session var with the information ... you could even put the info in a database before you use the function... anything is possible

[alt-f4]

I guess sometimes I just need to know if it is possible.
That gives me one more thign to do thanks a lot
Scott

[kjc]

Thanks for your replies. I will try it out in the next fews day and get back to you with the results.

Cheers

[kjc]

Are there any solutions which don't require GD to be installed. My web host doesn't have GD...

[poLka]

what about image magick? by the way... are there any discussions about IM at the moment?