PHP实现图片不变型裁剪及图片按比例裁剪的方法

本文实例讲述了PHP实现图片不变型裁剪及图片按比例裁剪的方法。分享给大家供大家参考，

本文实例讲述了PHP实现图片不变型裁剪及图片按比例裁剪的方法。分享给大家供大家参考，具体如下：

图片不变型裁剪

<?php
/**
 * imageCropper
 * @param string $source_path
 * @param string $target_width
 * @param string $target_height
 */
function imageCropper($source_path, $target_width, $target_height){
 $source_info = getimagesize($source_path);
 $source_width = $source_info[0];
 $source_height = $source_info[1];
 $source_mime = $source_info['mime'];
 $source_ratio = $source_height / $source_width;
 $target_ratio = $target_height / $target_width;
 if ($source_ratio > $target_ratio){
 // image-to-height
 $cropped_width = $source_width;
 $cropped_height = $source_width * $target_ratio;
 $source_x = 0;
 $source_y = ($source_height - $cropped_height) / 2;
 }elseif ($source_ratio < $target_ratio){
 //image-to-widht
 $cropped_width = $source_height / $target_ratio;
 $cropped_height = $source_height;
 $source_x = ($source_width - $cropped_width) / 2;
 $source_y = 0;
 }else{
 //image-size-ok
 $cropped_width = $source_width;
 $cropped_height = $source_height;
 $source_x = 0;
 $source_y = 0;
 }
 switch ($source_mime){
 case 'image/gif':
 $source_image = imagecreatefromgif($source_path);
 break;
 case 'image/jpeg':
 $source_image = imagecreatefromjpeg($source_path);
 break;
 case 'image/png':
 $source_image = imagecreatefrompng($source_path);
 break;
 default:
 return ;
 break;
 }
 $target_image = imagecreatetruecolor($target_width, $target_height);
 $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);
 // copy
 imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);
 // zoom
 imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);
 header('Content-Type: image/jpeg');
 imagejpeg($target_image);
 imagedestroy($source_image);
 imagedestroy($target_image);
 imagedestroy($cropped_image);
}
$filename = "8fcb7a0831b79c61.jpg";
imageCropper($filename,200,200);
?>

图片按比例裁剪

<?php
/**
 * imageZoom
 * @param string $file
 * @param double $zoom
 */
function imageZoom($filename,$zoom=0.6){
 //baseinfo
 $sourceImageInfo = getimagesize($filename);
 $sourceWidth = $sourceImageInfo[0];
 $sourceHeight = $sourceImageInfo[1];
 $sourceMine = $sourceImageInfo['mime'];
 $sourceRatio = $sourceWidth/$sourceHeight;
 $sourceX = 0;
 $sourceY = 0;
 //zoom
 $targetRatio = $zoom;
 //target-widht-height
 $targetWidth = $sourceWidth*$targetRatio;
 $targetHeight = $sourceHeight*$targetRatio;
 //init-params
 $sourceImage = null;
 switch($sourceMine){
 case 'image/gif':
 $sourceImage = imagecreatefromgif($filename);
 break;
 case 'image/jpeg':
 $sourceImage = imagecreatefromjpeg($filename);
 break;
 case 'image/png':
 $sourceImage = imagecreatefrompng($filename);
 break;
 default:
 return ;
 break;
 }
 //temp-target-image
 $tempSourceImage = imagecreatetruecolor($sourceWidth, $sourceHeight);
 $targetImage = imagecreatetruecolor($targetWidth,$targetHeight);
 //copy
 imagecopy($tempSourceImage, $sourceImage, 0, 0, $sourceX, $sourceY, $sourceWidth, $sourceHeight);
 //zoom
 imagecopyresampled($targetImage, $tempSourceImage, 0, 0, 0, 0, $targetWidth, $targetHeight, $sourceWidth, $sourceHeight);
 //header
 header('Content-Type: image/jpeg');
 //image-loading
 imagejpeg($targetImage);
 //destroy
 imagedestroy($tempSourceImage);
 imagedestroy($sourceImage);
 imagedestroy($targetImage);
}
$filename = "8fcb7a0831b79c61.jpg";
imageZoom($filename);
?>

希望本文所述对大家PHP程序设计有所帮助。