PHP实现图片裁剪及缩放函数,根据自定义的目标图高宽, 按目标图高宽比裁剪、缩放源图.

传入参数:

$source_path string 源图路径

$target_width integer 目标图宽度

$target_height integer 目标图高度

源图支持MIMETYPE: image/gif, image/jpeg, image/png。具体代码如下：

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);

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

imagejpeg($target_image);

imagedestroy($source_image);

imagedestroy($target_image);

imagedestroy($cropped_image);

}

更多信息请查看IT技术专栏