PHP image processing: Implementation of adding watermarks and thumbnails (custom functions: watermark, thumbnail)_PHP tutorial

Enough nonsense, post the code:

Copy the code The code is as follows:

/** **********************************
//Function: watermark($bigimg, $smallimg, $ coord = 1)
//Function: Add watermark
//Parameters:
$bigimg Required. Large picture--picture to be watermarked
$smallimg Required. Small image
$coord Optional. The position of the watermark in the large image,
1 upper left corner; 2 upper right corner; 3 lower right corner; 4 lower left corner; 5 middle
//Example: watermark('datu.png', 'xiaotu.png', 3); //Add watermark to datu.png. The watermark position is in the lower right corner
****************************** *****/
function watermark($bigimg, $smallimg, $coord = 1){
//Load two images and convert them into the encoding format recognized by PHP,
//Equivalent to imagecreate function, but what is created here is not 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 watermark - principle: copy the small image to the large image. Pay attention here to the calculation of coordinate values ​​
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], $si[1] ); break;
}
//Generate pictures in different formats based on the suffix name File
switch($bi[2]){
case 1:
imagegif($im1);break;
case 2;
imagejpeg($im1);break;
case 3;
imagepng($im1);break;
}
imagedestroy($im1);
}
/************************************************
/ /Function: thumbnail($srcimg, $multiple)
//Function: Generate a thumbnail image
//Parameters:
// $srcimg is required. Source image file name
// $multiple optional. Shrinking multiple, the default is 2 times, that is, reduced to 1/2 of the original size
//Note: Only supports gif, jpg, and png format images.
//Example: thumbnail('my picture.jpg', 5);
**************************** **********************/
function thumbnail($srcimg , $multiple = 2){
//Load the image and save its information to the array
$srcimg_arr = getimagesize($srcimg);
//Calculate the thumbnail multiple
$thumb_width = $srcimg_arr [0] / $multiple;
$thumb_height = $srcimg_arr[1] / $multiple;
//Judge: what format of image to create (convert to encoding recognized by PHP)
switch($srcimg_arr [2]){
case 1:
$im = imagecreatefromgif($srcimg);break;
case 2;
$im = imagecreatefromjpeg($srcimg);break;
case 3 ;
$im = imagecreatefrompng($srcimg);break;
}
//Start thumbnailing operation
$thumb = imagecreatetruecolor($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 these two functions at the same time when testing.
//watermark('datu.png','xiaotu.png',5);
thumbnail('abc.png',3);
?>

http://www.bkjia.com/PHPjc/322620.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/322620.htmlTechArticleStop talking nonsense, paste the code: Copy the code as follows: ?php /******** ****************************** //Function: watermark($bigimg, $smallimg, $coord = 1) //Function: Add Watermark/...