PHP生成缩略图的方法

PHP语法吸收了C语言、Java和Perl的'特点，利于学习，使用广泛，以下是为大家分享的PHP生成缩略图的方法，供大家参考借鉴，欢迎浏览!

<?php

function getCropper($source_path,$NewImagePath, $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);

// 图片裁剪

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

// 图片缩放

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

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

imagejpeg($target_image,$NewImagePath,100);

imagedestroy($source_image);

imagedestroy($target_image);

imagedestroy($cropped_image);

}

　　以下方法是生成缩略图，填充白边的方法

<?php

//生成缩略图，填充白边

function getCrops($src_path,$NewImagePath,$width,$height){

//源图对象

$src_image = imagecreatefromstring(file_get_contents($src_path));

$source_info = getimagesize($src_path);

$source_mime = $source_info['mime'];

$src_width = imagesx($src_image);

$src_height = imagesy($src_image);

switch ($source_mime)

{

case 'image/gif':

$src_image = imagecreatefromgif($src_path);

break;

case 'image/jpeg':

$src_image = imagecreatefromjpeg($src_path);

break;

case 'image/png':

$src_image = imagecreatefrompng($src_path);

break;

default:

return false;

break;

}

//生成等比例的缩略图

//$tmp_image_width = 0;

//$tmp_image_height = 0;

if ($src_width / $src_height >= $width / $height) {

$tmp_image_width = $width;

$tmp_image_height = round($tmp_image_width * $src_height / $src_width);

} else {

$tmp_image_height = $height;

$tmp_image_width = round($tmp_image_height * $src_width / $src_height);

}

$tmpImage = imagecreatetruecolor($tmp_image_width, $tmp_image_height);

imagecopyresampled($tmpImage, $src_image, 0, 0, 0, 0, $tmp_image_width, $tmp_image_height, $src_width, $src_height);

//添加白边

$final_image = imagecreatetruecolor($width, $height);

$color = imagecolorallocate($final_image, 255, 255, 255);

imagefill($final_image, 0, 0, $color);

$x = round(($width - $tmp_image_width) / 2);

$y = round(($height - $tmp_image_height) / 2);

imagecopy($final_image, $tmpImage, $x, $y, 0, 0, $tmp_image_width, $tmp_image_height);

//输出图片

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

imagejpeg($final_image,$NewImagePath,100);

imagedestroy($src_image);

imagedestroy($final_image);

}