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。