PHP image processing: watermark thumbnail implementation (custom function: watermark thumbnail)

 
<?php 
/************************************ 
//Function: watermark($bigimg, $smallimg, $coord = 1)
//Effect: add watermark
//Parameters:
$bigimg  Will be selected. The big picture -- Image to be watermarked  
$smallimg  Will be selected. Small pictures  
$coord  Optional. The position of the watermark in the large image,  
1  The top left corner.  2  The top right corner.  3  The lower right corner.  4  The lower left corner.  5  In the middle  
// Example:  watermark('datu.png', 'xiaotu.png', 3); // to datu.png Mark with a watermark in the lower right corner  
*************************************/ 
function watermark($bigimg, $smallimg, $coord = 1){ 
//Load two images and convert them to the encoding recognized by PHP,
//It's the same thing as the imagecreate function, except instead of creating an empty image.
$bi = getimagesize($bigimg); 
switch($bi[2]){ 
case 1: 
$im1 = imagecreatefromgif($bigimg);break; 
case 2; 
$im1 = imagecreatefromjpeg($bigimg);break; 
case 3; 
$im1 = imagecreatefrompng($bigimg);break; 
} 
$si = getimagesize($smallimg); 
switch($si[2]){ 
case 1: 
$im2 = imagecreatefromgif($smallimg);break; 
case 2; 
$im2 = imagecreatefromjpeg($smallimg);break; 
case 3; 
$im2 = imagecreatefrompng($smallimg);break; 
} 
//Create a watermark - how it works: copy a small image onto a large one. Notice the calculation of the coordinates here
switch($coord){ 
case 1: 
imagecopy ( $im1, $im2, 0, 0, 0, 0, $si[0], $si[1] ); break; 
case 2: 
imagecopy ( $im1, $im2, $bi[0]-$si[0], 0, 0, 0, $si[0], $si[1] ); break; 
case 3: 
imagecopy ( $im1, $im2, $bi[0]-$si[0], $bi[1]-$si[1], 0, 0, $si[0], $si[1] ); break; 
case 4: 
imagecopy ( $im1, $im2, 0, $bi[1]-$si[1], 0, 0, $si[0], $si[1] ); break; 
case 5: 
imagecopy ( $im1, $im2, ($bi[0]-$si[0])/2, ($bi[1]-$si[1])/2, 0, 0, $si[0], $si[1] ); break; 
} 
//Generate image files in different formats based on the suffix name
switch($bi[2]){ 
case 1: 
imagegif($im1);break; 
case 2; 
imagejpeg($im1);break; 
case 3; 
imagepng($im1);break; 
} 
imagedestroy($im1); 
} 
/************************************************ 
//Function: thumbnail($srcimg, $multiple)
//Action: generate a thumbnail image
//Parameters:
//$srcimg will choose. Source image file name
//$multiple optional. The thumbnail multiple, by default, is 2, which is reduced to 1/2
//Note: only GIF, JPG and PNG images are supported.
//Example: thumbnail(' my picture.jpg ', 5);
*************************************************/ 
function thumbnail($srcimg, $multiple = 2){ 
//Load the image and save its information into an array
$srcimg_arr = getimagesize($srcimg); 
//Calculate the thumbnail multiple
$thumb_width = $srcimg_arr[0] / $multiple; 
$thumb_height = $srcimg_arr[1] / $multiple; 
//Judgment: what format of image to create (converted to code recognized by PHP)
switch($srcimg_arr[2]){ 
case 1: 
$im = imagecreatefromgif($srcimg);break; 
case 2; 
$im = imagecreatefromjpeg($srcimg);break; 
case 3; 
$im = imagecreatefrompng($srcimg);break; 
} 
//Start thumbnail
$thumb = imagecreatetruecolor($thumb_width, $thumb_height); 
imagecopyresized($thumb, $im, 0, 0, 0 ,0, $thumb_width, $thumb_height, $srcimg_arr[0], $srcimg_arr[1]); 
switch($srcimg_arr[2]){ 
case 1: 
imagegif($thumb); break; 
case 2; 
imagejpeg($thumb); break; 
case 3; 
imagepng($thumb); break; 
} 
imagepng($thumb); 
imagedestroy($thumb); 
} 
//Do not use both functions when testing.
//watermark('datu.png','xiaotu.png',5); 
thumbnail('abc.png',3); 
?>