An analysis of the techniques of image processing in PHP introductory tutorial

The example in this paper describes the PHP image processing. Share to everyone for your reference, as follows:

demo1.php

<?php  //General generated image can be png,jpg,gif,bmp  //jpeg,wbmp  //First step, set file MIME type, output type text/html type is page type, default can not write  Change the output type to the image stream  header (' content-type:image/png; ');  The second step, create a graphics area, image background  //There are two ways to create, resource type, usually with the @ symbol, to prevent errors  //imagecreatetruecolor returns a resource handle  //This function creates an area of an image , the background is black  $im = Imagecreatetruecolor (200,200) when no padding is made;  The third step, there is a blank image area, drawing color, text called, line ah ...  ///Fill color Replace, the first to have a color filler  //imagecolorallocate--To assign a color to an image  $blue = Imagecolorallocate ($im, 0,102,255);  Fill the blue color to the background  //imagefill-area filled  imagefill ($im, 0,0, $blue);  Fourth, enter some lines on the blue background, text, etc.  $white = imagecolorallocate ($im, 255,255,255);  Imageline--Draw a line segment  imageline ($im, 0,0,200,200, $white);  Imageline ($im, 200,0,0,200, $white);  Imagestring--Draw a line of strings horizontally  imagestring ($im, 5,80,20, ' Mr.one ', $white);  Fifth step, output final graphics  //output images in PNG format to browser or file  imagepng ($im);  Sixth step, I want to empty all the resources  Imagedestroy ($IM); >

demo2.php

<?php  //SRC can insert all kinds of pictures  //demo1.php is actually a PNG image  header (' content-type:text/html; Charset=gbk ');  Echo ' 

demo3.php

<?php  //Simple Verification Code  //random number//  Why do you want to loop the number between 0-15?  //Because to achieve the simplest mix of letters and numbers  //16 binary 0-9 a-f  //dechex--decimal conversion to hexadecimal  //create a four-bit verification code for  ($i =0; $i <4; $i + + {    $nmsg. = Dechex (Mt_rand (0,15));  }  echo $nmsg;  Header (' content-type:image/png; ');  $im = Imagecreatetruecolor (75,25);  $blue = Imagecolorallocate ($im, 0,102,255);  $white = Imagecolorallocate ($im, 255,255,255);  Imagefill ($im, 0,0, $blue);  Imagestring ($im, 5,20,5, $nmsg, $white);  Imagepng ($im);  Imagedestroy ($im);? >

demo4.php

<?php  define (' __dir__ ', DirName (__file__). ' \\');  Load the existing image  header (' content-type:image/png; ');  Header (' content-type:image/jpeg; ');  Imagecreatefrompng--Create a new image from a PNG file or URL  //load an image with image, you can edit the image  //In the loaded image, add a small watermark  $im = Imagecreatefrompng (__dir__. ' Ss.png ');  $im = Imagecreatefromjpeg (' xx.jpg ');  $white = Imagecolorallocate ($im, 255,255,255);  Imagestring ($im, 5,10,10, ' http://www.oneStopWeb.cn ', $white);  Imagepng ($im);  Imagejpeg ($im);  Imagedestroy ($im);? >

demo5.php

<?php  define (' __dir__ ', DirName (__file__). ' \\');  Load the existing image  header (' content-type:image/png; ');  Header (' content-type:image/jpeg; ');  Imagecreatefrompng--Create a new image from a PNG file or URL  //load an image with image, you can edit the image  //In the loaded image, add a small watermark  $im = Imagecreatefrompng (__dir__. ' Ss.png ');  $im = Imagecreatefromjpeg (' xx.jpg ');  $white = Imagecolorallocate ($im, 255,255,255);  Imagestring ($im, 5,10,10, ' http://www.oneStopWeb.cn ', $white);  Font fonts must also support Chinese  $font = ' C:\WINDOWS\Fonts\SIMHEI. TTF ';  Font file  $text = iconv (' GBK ', ' utf-8 ', ' read who asks the chant ');  Using the system-provided font  //second parameter, is the size of the font, the third parameter is the rotation angle, the 4,5 parameter is the coordinate  imagettftext ($im, 20,10,50,100, $white, $font, $text);  Imagepng ($im);  Imagejpeg ($im);  Imagedestroy ($im);? >

demo6.php

<?php  //thumbnail, not only the size of the surface has changed, the capacity has changed  //is really changed, not the surface of the narrowing  define (' __dir__ ', DirName (__file__). ' \\');  Header (' content-type:image/png; ');  GetImageSize--Get the image size  //Get to the original length and height  list ($width, $height) = getimagesize (__dir__. ') Ss.png ');  Scale the original image to 40%  $_width = $width * 0.4;  $_height = $height * 0.4;  Create a new diagram  $im = Imagecreatetruecolor ($_width,$_height);  The following work is to load the original picture, copy the original image to the new diagram  //Load the original  $_im = Imagecreatefrompng (__dir__. ' Ss.png ');  Resample the original image, copy it to the new diagram, and finally output the//imagecopyresampled at a scale of 0.4-resampling the  copy portion of the images and resizing  imagecopyresampled ($im, $_im, 0,0,0,0,$_width,$_height, $width, $height);  Output the new diagram  imagepng ($im);  The second parameter does not need, direct null over  //third parameter, is 0-100 to adjust the sharpness of JPG  //If it is imagepng, then all are HD  //imagejpeg ($im, null,50);  Destruction of  Imagedestroy ($im);  Imagedestroy ($_im);? >

I hope this article is helpful to you in PHP programming.