php生成縮略圖

1、PHP令我們驚喜的就是在圖形圖象處理方面要憂于ASP，用GD庫PHP就可以輕松的實(shí)現(xiàn)縮略圖。這一篇文章我們的目的就是用GD來生成縮略圖，PHP可以把縮略圖直接生成輸送到瀏覽器也可以以文件的形式把其存儲到硬盤當(dāng)中。在生成縮略圖的過程當(dāng)中我們需要用到GD庫當(dāng)中的幾個(gè)函數(shù)：getimagesize(string filename ,array var),取得圖像的信息，返回值是一人array,包括幾項(xiàng)信息$var0-返回圖像的width,$var1-返回 height,2返回圖像文件的type,4返回的是與<img src="">當(dāng)中的wdith,height有關(guān)的w

2、idth="",height=""信息。imageX(resource image)imageY(resource image)  返回圖像的寬和高imagecopyresized(des img,src img,int des_x,int des_y,int src_x,int src_y,int des_w,int des_h,int src_w,int src_y)  復(fù)制并截取區(qū)域圖像imagecreatetruecolor(int width,int height)  創(chuàng)建一個(gè)真彩圖imagejpeg(resour

3、ce image) 下面就是Code:<?php# Constantsdefine(IMAGE_BASE, '/var/www/html/mbailey/images');define(MAX_WIDTH, 150);define(MAX_HEIGHT, 150);# Get image location$image_file = str_replace('.', '', $_SERVER'QUERY_STRING');$image_path = IMAGE_BASE . "/$image_file"#

4、Load image$img = null;$ext = strtolower(end(explode('.', $image_path);if ($ext = 'jpg' | $ext = 'jpeg')     $img = imagecreatefromjpeg($image_path); else if ($ext = 'png')     $img = imagecreatefrompng($image_path);# Only if you

5、r version of GD includes GIF support else if ($ext = 'gif')     $img = imagecreatefrompng($image_path);# If an image was successfully loaded, test the image for sizeif ($img)     # Get image size and scale ratio    $width = imagesx(

6、$img);    $height = imagesy($img);    $scale = min(MAX_WIDTH/$width, MAX_HEIGHT/$height);    # If the image is larger than the max shrink it    if ($scale < 1)         $new_widt

7、h = floor($scale*$width);        $new_height = floor($scale*$height);        # Create a new temporary image        $tmp_img = imagecreatetruecolor($new_width, $new_height); &#

8、160;      # Copy and resize old image into new image        imagecopyresized($tmp_img, $img, 0, 0, 0, 0,$new_width, $new_height, $width, $height);        imagedestroy($img);   

9、;     $img = $tmp_img;    # Create error image if necessaryif (!$img)     $img = imagecreate(MAX_WIDTH, MAX_HEIGHT);    imagecolorallocate($img,0,0,0);    $c = imagecolorallocate($img,70,70,70);&

10、#160;   imageline($img,0,0,MAX_WIDTH,MAX_HEIGHT,$c2);    imageline($img,MAX_WIDTH,0,0,MAX_HEIGHT,$c2);# Display the imageheader("Content-type: image/jpeg");imagejpeg($img);?> 我們把上面的Code存儲為test.php,然后通過test.php?image name的形式來訪問，結(jié)果會讓你驚喜的，因?yàn)樵谶@里你看到了PHP的優(yōu)點(diǎn)，它可以讓ASP相形見絀。上 面的這段代碼當(dāng)中我們通過end(explode(".",$image_path)來取得文件的擴(kuò)展名，但是我感覺還是不理想。這樣是能夠取得文件的類 型的，因?yàn)閑nd()函數(shù)會跳到本array的最后一個(gè)單元，但是如果我們采用getima