图片生成缩略图代码

图片生成缩略图代码

<?php
# Constants
define("IMAGE_BASE", './');
define("MAX_WIDTH", 150);
define("MAX_HEIGHT", 150);

# Get image locationstr_replace('..', '', $_SERVER['QUERY_STRING']);
$image_file = 't.jpg';
$image_path = IMAGE_BASE . "$image_file";

# Load image
$img = null;
$ext = strtolower(end(explode('.', $image_path)));
if ($ext == 'jpg' || $ext == 'jpeg') {
     $img = imagecreatefromjpeg($image_path);
} else if ($ext == 'png') {
     $img = @imagecreatefrompng($image_path);
# Only if your version of GD includes GIF support
} else if ($ext == 'gif') {
     $img = @imagecreatefrompng($image_path);
}

# If an image was successfully loaded, test the image for size
if ($img) {

     # Get image size and scale ratio
     $width = imagesx($img);
     $height = imagesy($img);
     $scale = min(MAX_WIDTH/$width, MAX_HEIGHT/$height);

     # If the image is larger than the max shrink it
     if ($scale < 1) {
         $new_width =150; //floor($scale*$width);
         $new_height =150;// floor($scale*$height);

         # Create a new temporary image
         $tmp_img = imagecreatetruecolor($new_width, $new_height);

         # Copy and resize old image into new image
         imagecopyresized($tmp_img, $img, 0, 0, 0, 0,$new_width, $new_height, $width, $height);
         imagedestroy($img);
         $img = $tmp_img;
     }
}

# Create error image if necessary
if (!$img) {
     $img = imagecreate(MAX_WIDTH, MAX_HEIGHT);
     imagecolorallocate($img,0,0,0);
     $c = imagecolorallocate($img,70,70,70 );
     imageline($img,0,0,MAX_WIDTH,MAX_HEIGHT,$c2);
     imageline($img,MAX_WIDTH,0,0,MAX_HEIGHT,$c2);
}

# Display the image
header("Content-type: image/jpeg");
imagejpeg($img);
imagedestroy($img);
?>