GD Library (b)

PHP image Processing
1. Picture Background Management
Use the Imagecreate () and Imagecreatetruecolor () functions to create canvas resources. But if you already have a picture to work with, just use this image as a canvas resource, which is what we call creating a picture background.
Imagecreatefromjpeg ($path)
Imagecreatefrompng ($path)
Imagecreatefromgif ($path)

Get picture type width height etc getimagesize ($path)

2. Zoom in on the picture
Imagecopyresampled (Dst_img,src_img,dst_x,dst_y,src_x,src_y,dst_w,dst_h,src_w,src_h)
Custom Image Indent function:

1 functionThumb$filename,$width=200,$height=200){2 //get the width and height of the original image3 List($width _orig,$height _orig)=getimagesize($filename);4 5 //proportional to the ratio of width to height6 if($width&& ($width _orig<$height _orig)){7 $width=($height/$height _orig)*$width _orig;8}Else{9 $height=($width/$width _orig)*$height _orig;Ten } One  A $im=imagecreatetruecolor ($width,$height); - $image=imagecreatefromjpeg ($filename);//indent JPEG format -Imagecopyresampled ($im,$image, 0,0,0,0,$width,$height,$width _orig，$height _orig); the  -Imagejpeg ($im,$filename, 100); -  -Imagedestroy ($im); +Imagedestroy ($image); -}

3. Picture clipping
Custom clipping functions:

1 functionCut$filename,$x,$y,$width,$height){2 //Create a background resource3 $back=imagecreatefromjpeg ($filename);4 //Create save cropped resource5 $im=imagecreatetruecolor ($width,$height);6 //cropping7Imagecopyresampled ($im,$back, 0, 0,$x,$y,$width,$height,$width，$height);8 //overwrite the original, if you do not want to overwrite the additive prefix9Imagejpeg ($im,$filename);Ten  OneImagedestroy ($im); AImagedestroy ($back);

4. Add a watermark
Custom watermark Functions:

1 functionWatermark$filename,$water){2 //Get the width height of the background graph3 List($b _w,$b _h)=getimagesize($filename);4 //get the width and height of the watermark5 List($w _w,$w _h)=getimagesize($water);6 //The random position of the watermark in the background map7 $posx=Rand(0, ($b _w-$w _w));8 $posy=Rand(0, ($b _h-$w _h));9 //creating background and watermark ResourcesTen $back=imagecreatefromjpeg ($filename); One $water=imagecreatefrompng ($water); A //Add Watermark -Imagecopy ($back,$water,$posx,$posy, 0, 0,$w _w,$w _h); - //Save Watermark Map theImagejpeg ($back,$filename); - //Freeing Resources -Imagedestroy ($water); -Imagedestroy ($back); +}

5. Picture rotation
Custom Rotation functions:

1 functionRotate$filename,$degrees){2 //Create an image resource3 $im=imagecreatefromjpeg ($filename);4 //rotate by the specified angle5 $rotate=imagerotate ($im,$degrees, 0);6 //Save the post-rotation diagram7Imagejpeg ($im,$filename);8}

GD Library (b)