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，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。