سوال: کاهش سایز تصاویر توسط php

من برای تغییر سایز تصاویرم از اسکریپت زیر استفاده می کنم نمی دونم چرا کار نمی کنه دلیلش چی می تونه باشه...؟

imgsize.php

<?php

header ("Content-type: image/jpeg");

/*

JPEG / PNG Image Resizer

Parameters (passed via URL):



img = path / url of jpeg or png image file



percent = if this is defined, image is resized by it's

          value in percent (i.e. 50 to divide by 50 percent)



w = image width



h = image height



constrain = if this is parameter is passed and w and h are set

            to a size value then the size of the resulting image

            is constrained by whichever dimension is smaller



Requires the PHP GD Extension



Outputs the resulting image in JPEG Format



By: Michael John G. Lopez - www.sydel.net

Filename : imgsize.php

*/



$img = $_GET['img'];

$percent = $_GET['percent'];

$constrain = $_GET['constrain'];

$w = $_GET['w'];

$h = $_GET['h'];



// get image size of img

$x = @getimagesize($img);

// image width

$sw = $x[0];

// image height

$sh = $x[1];



if ($percent > 0) {

	// calculate resized height and width if percent is defined

	$percent = $percent * 0.01;

	$w = $sw * $percent;

	$h = $sh * $percent;

} else {

	if (isset ($w) AND !isset ($h)) {

		// autocompute height if only width is set

		$h = (100 / ($sw / $w)) * .01;

		$h = @round ($sh * $h);

	} elseif (isset ($h) AND !isset ($w)) {

		// autocompute width if only height is set

		$w = (100 / ($sh / $h)) * .01;

		$w = @round ($sw * $w);

	} elseif (isset ($h) AND isset ($w) AND isset ($constrain)) {

		// get the smaller resulting image dimension if both height

		// and width are set and $constrain is also set

		$hx = (100 / ($sw / $w)) * .01;

		$hx = @round ($sh * $hx);



		$wx = (100 / ($sh / $h)) * .01;

		$wx = @round ($sw * $wx);



		if ($hx < $h) {

			$h = (100 / ($sw / $w)) * .01;

			$h = @round ($sh * $h);

		} else {

			$w = (100 / ($sh / $h)) * .01;

			$w = @round ($sw * $w);

		}

	}

}



$im = @ImageCreateFromJPEG ($img) or // Read JPEG Image

$im = @ImageCreateFromPNG ($img) or // or PNG Image

$im = @ImageCreateFromGIF ($img) or // or GIF Image

$im = false; // If image is not JPEG, PNG, or GIF



if (!$im) {

	// We get errors from PHP's ImageCreate functions...

	// So let's echo back the contents of the actual image.

	readfile ($img);

} else {

	// Create the resized image destination

	$thumb = @ImageCreateTrueColor ($w, $h);

	// Copy from image source, resize it, and paste to image destination

	@ImageCopyResampled ($thumb, $im, 0, 0, 0, 0, $w, $h, $sw, $sh);

	// Output resized image

	@ImageJPEG ($thumb);

}

?>

طریقه استفاده :

                     <center><img src="'.root.'inc/imgsize.php?w=450&h=250&img='.root.'upload/'.$row['pic'].'" alt="'.$row['title'].'" title="'.$row['title'].'" class="picnews" ></center>