php 图像裁剪(自定义裁剪图片大小)

 

<?php

/**

* 图像裁剪

* @param $title string 原图路径

* @param $content string 需要裁剪的宽

* @param $encode string 需要裁剪的高

*/

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;



// 源图过高

if ($source_ratio > $target_ratio)

{

$cropped_width = $source_width;

$cropped_height = $source_width * $target_ratio;

$source_x = 0;

$source_y = ($source_height - $cropped_height) / 2;

}

// 源图过宽

elseif ($source_ratio < $target_ratio)

{

$cropped_width = $source_height / $target_ratio;

$cropped_height = $source_height;

$source_x = ($source_width - $cropped_width) / 2;

$source_y = 0;

}

// 源图适中

else

{

$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 false;

break;

}



$target_image = imagecreatetruecolor($target_width, $target_height);

$cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);



// 裁剪

imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);

// 缩放

imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);



//保存图片到本地(两者选一)

//$randNumber = mt_rand(00000, 99999). mt_rand(000, 999);

//$fileName = substr(md5($randNumber), 8, 16) .".png";

//imagepng($target_image,'./'.$fileName);

//imagedestroy($target_image);



//直接在浏览器输出图片(两者选一)

header('Content-Type: image/jpeg');

imagepng($target_image);

imagedestroy($target_image);

imagejpeg($target_image);

imagedestroy($source_image);

imagedestroy($target_image);

imagedestroy($cropped_image);

}



//调用

//imagecropper('./img033.jpg',300,300);

imagecropper('./img033.jpg',140,140);

//imagecropper('./img033.jpg',55,55);

?>