Code case for customizing Image Center clipping function in PHP

This paper describes the custom Image Center clipping function implemented by PHP. Share to everyone for your reference, as follows:

The general idea of Image center cut:

1. First zoom the image so that the scaled image can cover the cut area exactly. (imagecopyresampled-resample Copy part of image and resize)

2. Place the zoomed image in the middle of the clipping area. (Part of the imagecopy-copy image)

3. Cut the image and save it. (Imagejpeg | Imagepng | imagegif-output image to browser or file)

Specific code:

================== Zoom clipping Function ====================/** * Center crop picture * @param string $source [Original path] * @param int $width [set width] * @pa RAM int $height [Set height] * @param string $target [target path] * @return bool [clipping result] */function Image_center_crop ($source, $width,  $height, $target) {if (!file_exists ($source)) return false;      /* Load image by Type */switch (Exif_imagetype ($source)) {case Imagetype_jpeg: $image = Imagecreatefromjpeg ($source);    Break      Case Imagetype_png: $image = Imagecreatefrompng ($source);    Break      Case Imagetype_gif: $image = Imagecreatefromgif ($source);  Break  } if (!isset ($image)) return false;  /* Get image size information */$target _w = $width;  $target _h = $height;  $source _w = Imagesx ($image);  $source _h = Imagesy ($image);  /* Calculate clipping width and height */$judge = (($source _w/$source _h) > ($target _w/$target _h)); $resize _w = $judge?  ($source _w * $target _h)/$source _h: $target _w; $resize _h =! $judge?  ($source _h * $target _w)/$source _w: $target _h; $start _x = $judge? ($resize_w-$target _w)/2:0; $start _y =! $judge?  ($resize _h-$target _h)/2:0;  /* Draw Center Zoom image */$resize _img = Imagecreatetruecolor ($resize _w, $resize _h);  Imagecopyresampled ($resize _img, $image, 0, 0, 0, 0, $resize _w, $resize _h, $source _w, $source _h);  $target _img = Imagecreatetruecolor ($target _w, $target _h);  Imagecopy ($target _img, $resize _img, 0, 0, $start _x, $start _y, $resize _w, $resize _h);  /* Save the picture to file */if (!file_exists (DirName ($target))) mkdir (DirName ($target), 0777, true);      Switch (Exif_imagetype ($source)) {case Imagetype_jpeg:imagejpeg ($target _img, $target);    Break      Case Imagetype_png:imagepng ($target _img, $target);    Break      Case Imagetype_gif:imagegif ($target _img, $target);  Break }//return Boolval (file_exists ($target))//php5.5 the Boolval () function is used to get the returned Boolean value return File_exists ($target)? true:false;// Compatible with low-version PHP notation}

The ================== function uses the way ====================//the original picture $source = ' ... /source/img/middle.jpg '; $width = 480; Cropped width $height = 480;//cropped height//cropped picture storage directory $target = ' ... /source/temp/resize.jpg ';//Save to target folder if (Image_center_crop ($source, $width, $height, $target)) {  echo ' original 1440* 900:  ';  echo "
Operating effect:

The original 1440*900 is:


 

After the modified picture 480*480:

Similarly, 480*320, 800*600, and other dimensions of the image only need to modify the corresponding parameters.

Attached: Problems encountered in code testing

Error: Call an undefined function exif_imagetype ()

Workaround:

Open extensionextension=php_exif.dll

and extension=php_mbstring.dll put it to the extension=php_exif.dll front

another: boolval() function is a function that can be used above the PHP5.5 version , this article tests the code for a compatible low version, using the following statement instead:



return file_exists ($target)? True:false;