i hav the new dimmensions for an image and the location of the file, how do i do this.
$new_image_width
$new_image_height
$image_file_location
basic image resize
i use the code below. place it in a file called thumbnail.php, and then you can use the url
thumbnail.php?filename=YOURFILE&x=WIDTH&y=HEIGHT
from any page, ie
<IMG SRC="thumbnail.php?filename=me.jpg&x=100&y=100">
also this has the benefit of not distorting the image - it will maintain the aspect ration of the image when you resize.
here is the code
<?php
function loadjpeg($path, $max_x, $max_y) {
$im = @imagecreatefromjpeg($path);
if (!$im) {
$im = imagecreate(150, 30);
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
imagestring($im, 1, 5, 5, "Error loading $path", $tc);
}
if ($max_x != 0 && $max_y != 0) {
$x = imagesx($im);
$y = imagesy($im);
if ($x > $max_x) {
$y = (int)floor($y * ($max_x / $x));
$x = $max_x;
}
if ($y > $max_y) {
$x = (int)floor($x * ($max_y / $y));
$y = $max_y;
}
if (imagesx($im) != $x || imagesy($im) != $y) {
$tmp = imagecreate($x, $y);
imagecopyresized($tmp, $im, 0, 0, 0, 0, $x, $y, imagesx($im), imagesy($im));
imagedestroy($im);
$im = $tmp;
}
}
imagejpeg($im);
}
$filename = $_GET['filename'];
$width = $_GET['x'];
$height = $_GET['y'];
loadjpeg($filename, $width, $height);
?>
note: if you are using GD 2.0 or above, replace imagecopyresized with imagecopyresampled, and the quality of the thumbnail will be better.
this isn't my work, but i don't know who the credit should go to.
adam
thanks for the reply, but this is not quite what im looking for.
I need a php script that can resize an actual image and then replace the original with the resized version.
Here is a short script I made a while back which creates thumbnails in various forms depending on the input recieved via HTTP GET.
examples:
1) 'create_thumb.php?img=IMG1.JPG&limit_width=640&limit_height=480'
Creates a thumbnail, preserving the aspect ratio of the original image (so it isnt squished/stretched at all) and limits the size to fitting inside a 640 x 480 pixel box.
2) 'create_thumb.php?img=IMG1.JPG&limit_width=640&limit_height=480&stretch'
Same as before except the image is stretched to fit exactly in a 640 x 480 box.
Notes: The script will attempt to cache the file with the name <original_file_name>thumb<pixel_width>x<pixel_height>_<scale/stretch> unless the variable 'no_cache' or 'no_write' exists in the HTTP GET stream; if the cache is successful, then all recurring requests will be loaded from the cache file.
example of http url which tells the script not to cache:
'create_thumb.php?img=IMG1.JPG&limit_width=640&limit_height=480&stretch&no_cache'
<?
// Jon Newman - jnewman (at) oplink (d0t) net (2003)
function create_thumb($im_source, $max_x, $max_y, $output_file, $stretch=FALSE)
{
$im_prop=getimagesize($im_source);
if(!$im_prop[2]==2)
return(0);
else
{
$src_im=imagecreatefromjpeg($im_source);
$src_x=imagesx($src_im);
$src_y=imagesy($src_im);
$thumb_x=$src_x;
$thumb_y=$src_y;
if($src_x>$max_x && $src_x>=$src_y)
{
$thumb_x=$max_x;
if(!$stretch)
$thumb_y=(int)(($max_x/$src_x)*$src_y);
else
$thumb_y=$max_y;
}
else if($src_y>$max_y && $src_y>$src_x)
{
$thumb_y=$max_y;
if(!$stretch)
$thumb_x=(int)(($max_y/$src_y)*$src_x);
else
$thumb_x=$max_x;
}
if(($thumb_y=="0") && ($thumb_x=="0"))
return(0);
elseif($thumb_y == "0")
{
$scale_x=$thumb_x/($src_x-1);
$thumb_y=$src_y*$scale_x;
}
elseif($thumb_x=="0")
{
$scale_y=$thumb_y/($src_y-1);
$thumb_x=$src_x*$scale_y;
}
$thumb_x=(int)($thumb_x);
$thumb_y=(int)($thumb_y);
$dest_im=imagecreatetruecolor($thumb_x, $thumb_y);
if(!imagecopyresized($dest_im, $src_im, 0, 0, 0, 0, $thumb_x, $thumb_y, $src_x, $src_y))
{
imagedestroy($src_im);
imagedestroy($dest_im);
return(0);
}
else
{
imagedestroy($src_im);
if($output_file!='')
{
if(@imagejpeg($dest_im,$output_file))
{
imagedestroy($dest_im);
return(-1);
}
else
{
imagejpeg($dest_im);
imagedestroy($dest_im);
return(0);
}
}
else
{
imagejpeg($dest_im);
imagedestroy($dest_im);
return(-1);
}
imagedestroy($dest_im);
}
return(0);
}
}
header("Content-type: image/jpeg");
if(isset($_GET['img']) && file_exists($_GET['img']))
{
$_file=$_GET['img'].'_thumb_'.$_GET['limit_width'].'x'.$_GET['limit_height'].(isset($_GET['stretch']) ? '_stretch' : '_scale');
if(!file_exists($_file) || isset($_GET['no_cache']))
{
if(($t=create_thumb($_GET['img'],(isset($_GET['limit_width']) ? $_GET['limit_width'] : 100),(isset($_GET['limit_height']) ? $_GET['limit_height'] : 100),(!isset($_GET['nowrite']) && !isset($_GET['no_cache']) ? $_file : ''),(isset($_GET['stretch']) ? TRUE : FALSE)))==-1)
imagejpeg(@imagecreatefromjpeg($_file));
else
{
$im=imagecreatetruecolor(100,100);
$background_color=imagecolorallocate($im, 0, 0, 0);
$text_color=imagecolorallocate($im, 233, 14, 91);
imagestring($im, 2, 35, 40, ": X :", $text_color);
imagejpeg($im);
}
}
else
{
imagejpeg(@imagecreatefromjpeg($_file));
}
}
else
{
$im=imagecreatetruecolor(100,100);
$background_color=imagecolorallocate($im, 0, 0, 0);
$text_color=imagecolorallocate($im, 233, 14, 91);
imagestring($im, 2, 35, 40, ": X :", $text_color);
imagejpeg($im);
}
?>
Although this doesn't do exactly what you want you should be able to modify it to suit your needs.
i still do not seem to be making my point clear. i need the script to OPEN a image on the server (eg. pics/001.jpg) RESIZE to a height and width i can easily specify. Once its resized it i need 2 to replace the old image. (overrite pics/001.jpg)
This is why it's a mistake to just give people the code - they never learn from it.
You want to open an [man]image[/man] on the server. Okay, there are functions for that: [man]imagecreatefromjpeg[/man] springs to mind.
You want to resize the image. Right, there are functions for that: [man]imagecopyresize[/man] is the obvious one, but [man]imagecopyresampled[/man] gives the better result.
And then you want to save it. Fine. [man]imagejpeg[/man] will do that.
Read those pages. You will find examples of their use.
Ok...if you want someone to write the script for you...then go somewhere else. What I gave you is 95% of what you needed and if you can't figure out how to change it to your needs...then uh....nevermind 
You may think about learning how to program before actually attempting such a thing...
well based on what functions i was told to use and those other scripts i've written this.
<?php
$currentimagesize = getimagesize("pics/Dane_bike_pic.jpg");
$image_width = $currentimagesize[0];
$image_height= $currentimagesize[1];
//calc
$new_image_width = 600;
$divide_value = $image_width / $new_image_width ;
$new_image_height = $image_height / $divide_value ;
$bikepicimgoriginal = imagecreatefromjpeg("pics/Dane_bike_pic.jpg");
$bikepicimgnew = imagecopyresized ( $bikepicimgnew, $bikepicimgoriginal, 0, 0, 0, 0, $new_image_width, $new_image_height, $image_width, $image_height);
imagejpeg($bikepicimgnew);
?>
at the momment this doesnt work, i was wonderin wot do i have to do to make it work. the error messages are
Warning: imagecopyresized(): supplied argument is not a valid Image resource in /home/dc/public_html/test.php on line 14
Warning: imagejpeg(): supplied argument is not a valid Image resource in /home/dc/public_html/test.php on line 15
If image magick is installed in the server you can try convert:
<?
$the_path ="/....../images";
$file_name ="test.jpg";
exec("convert -size 250x250 $the_path/$file_name -resize 250x250 +profile \"*\" $the_path/$file_name");
?>
no it isnt installed on my server, but cheers for the reply.
So does any1 kno how i could fix my script.
9 days later
Warning: imagecopyresized(): supplied argument is not a valid Image resource in /home/dc/public_html/test.php on line 14
Warning: imagejpeg(): supplied argument is not a valid Image resource in /home/dc/public_html/test.php on line 15
This suggests to me that the variable you are passing to these functions does not contain the path to an image