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Code summary of php's various image processing functions

  • 2020-07-21 07:20:55
  • OfStack

1. Create image resources

imagecreatetruecolor(width,height);
imagecreatefromgif(image name);
imagecreatefrompng(image name);
imagecreatefromjpeg(image name); Draw various images imagegif(image resources, save path);
imagepng()
imagejpeg();

2. Get image attributes

imagesx (res / / width
imagesy (res / / height
getimagesize(file path)
Returns 1 array with 4 cells. Index 0 contains the pixel value of the image width, and index 1 contains the pixel value of the image height. Index 2 is the token for the image type: 1 = GIF, 2 = JPG, 3 = PNG, 4 = SWF, 5 = PSD, 6 = BMP, 7 = TIFF(intel byte order), 8 = TIFF(motorola byte order), 9 = JPC, 10 = JP2, 11 = JPX, 12 = JB2, 13 = SWC, 14 = IFF, 15 = WBMP, 16 = XBM. These tags correspond to the new IMAGETYPE constant added to PHP 4.3.0. Index 3 is a text string that reads "height="yyy" width="xxx" and can be used directly for the IMG tag.
Destruction of image resources
imagedestroy(Image resources);

3. Transparent handling

PNG and jpeg were normal in transparent color, while gif was abnormal

imagecolortransparent(resource image [,int color])// Sets a color to transparent
imagecolorstotal()
imagecolorforindex();

4. Cropping of pictures

imagecopyresized()
imagecopyresampled();

5. Watermark (text, picture)

String encoding conversion string iconv (string $in_charset, string $out_charset, string $str)

6. Image rotation

imagerotate (); // Set the Angle of the picture to flip

7. Flip the picture

Flip along the X axis along the Y axis

8. Sharpening

imagecolorsforindex()

imagecolorat()

In picture painted graphics $img = imagecreatefromgif (". / images map. gif "); 


 $red= imagecolorallocate($img, 255, 0, 0);
 imageline($img, 0, 0, 100, 100, $red);
 imageellipse($img, 200, 100, 100, 100, $red);
 imagegif($img, "./images/map2.gif");
 imagedestroy($img);

Image normal zoom 


$filename="./images/hee.jpg";
 $per=0.3;
 list($width, $height)=getimagesize($filename);
 $n_w=$width*$per;
 $n_h=$width*$per;
 $new=imagecreatetruecolor($n_w, $n_h);
 $img=imagecreatefromjpeg($filename);
// Copy part of image and adjust 
 imagecopyresized($new, $img,0, 0,0, 0,$n_w, $n_h, $width, $height);
// Image output new image, save as 
 imagejpeg($new, "./images/hee2.jpg");
 imagedestroy($new);
 imagedestroy($img);

Image scale, no processing of transparent color 

function thumn($background, $width, $height, $newfile) {
 list($s_w, $s_h)=getimagesize($background);// Gets the height and width of the original image 
 if ($width && ($s_w < $s_h)) {
     $width = ($height / $s_h) * $s_w;
 } else {
     $height = ($width / $s_w) * $s_h;
 }
 $new=imagecreatetruecolor($width, $height);
 $img=imagecreatefromjpeg($background);
 imagecopyresampled($new, $img, 0, 0, 0, 0, $width, $height, $s_w, $s_h);
 imagejpeg($new, $newfile);
 imagedestroy($new);
 imagedestroy($img);
}
thumn("images/hee.jpg", 200, 200, "./images/hee3.jpg");

gif transparent color treatment 

function thumn($background, $width, $height, $newfile) {
 list($s_w, $s_h)=getimagesize($background);
 if ($width && ($s_w < $s_h)) {
     $width = ($height / $s_h) * $s_w;
 } else {
     $height = ($width / $s_w) * $s_h;
 }
 $new=imagecreatetruecolor($width, $height);
 $img=imagecreatefromgif($background);
 $otsc=imagecolortransparent($img);
 if($otsc >=0 && $otst < imagecolorstotal($img)){// Judge index color 
  $tran=imagecolorsforindex($img, $otsc);// Index color value 
  $newt=imagecolorallocate($new, $tran["red"], $tran["green"], $tran["blue"]);
  imagefill($new, 0, 0, $newt);
  imagecolortransparent($new, $newt);
 }
 imagecopyresized($new, $img, 0, 0, 0, 0, $width, $height, $s_w, $s_h);
 imagegif($new, $newfile);
 imagedestroy($new);
 imagedestroy($img);
}
thumn("images/map.gif", 200, 200, "./images/map3.gif");

Image cropping 

function cut($background, $cut_x, $cut_y, $cut_width, $cut_height, $location){
 $back=imagecreatefromjpeg($background);
 $new=imagecreatetruecolor($cut_width, $cut_height);
 imagecopyresampled($new, $back, 0, 0, $cut_x, $cut_y, $cut_width, $cut_height,$cut_width,$cut_height);
 imagejpeg($new, $location);
 imagedestroy($new);
 imagedestroy($back);
}
cut("./images/hee.jpg", 440, 140, 117, 112, "./images/hee5.jpg");

Image watermarking

Text watermarking 


function mark_text($background, $text, $x, $y){
  $back=imagecreatefromjpeg($background);
  $color=imagecolorallocate($back, 0, 255, 0);
  imagettftext($back, 20, 0, $x, $y, $color, "simkai.ttf", $text);
  imagejpeg($back, "./images/hee7.jpg");
  imagedestroy($back);
 }
 mark_text("./images/hee.jpg", " In detail PHP", 150, 250);
// Image watermarking 
function mark_pic($background, $waterpic, $x, $y){
$back=imagecreatefromjpeg($background);
$water=imagecreatefromgif($waterpic);
$w_w=imagesx($water);
$w_h=imagesy($water);
imagecopy($back, $water, $x, $y, 0, 0, $w_w, $w_h);
imagejpeg($back,"./images/hee8.jpg");
imagedestroy($back);
imagedestroy($water);
}
mark_pic("./images/hee.jpg", "./images/gaolf.gif", 50, 200);

Image rotation 


$back=imagecreatefromjpeg("./images/hee.jpg");
 $new=imagerotate($back, 45, 0);
 imagejpeg($new, "./images/hee9.jpg");

The picture is flipped horizontally and flipped vertically 

function turn_y($background, $newfile){
  $back=imagecreatefromjpeg($background);
  $width=imagesx($back);
  $height=imagesy($back);
  $new=imagecreatetruecolor($width, $height);
  for($x=0; $x < $width; $x++){
   imagecopy($new, $back, $width-$x-1, 0, $x, 0, 1, $height);
  }
  imagejpeg($new, $newfile);
  imagedestroy($back);
  imagedestroy($new);
 }
 function turn_x($background, $newfile){
  $back=imagecreatefromjpeg($background);
  $width=imagesx($back);
  $height=imagesy($back);
  $new=imagecreatetruecolor($width, $height);
  for($y=0; $y < $height; $y++){
   imagecopy($new, $back,0, $height-$y-1, 0, $y, $width, 1);
  }
  imagejpeg($new, $newfile);
  imagedestroy($back);
  imagedestroy($new);
 }
 turn_y("./images/hee.jpg", "./images/hee11.jpg");
 turn_x("./images/hee.jpg", "./images/hee12.jpg");

Image sharpening 


function sharp($background, $degree, $save){
 $back=imagecreatefromjpeg($background);
 $b_x=imagesx($back);
 $b_y=imagesy($back);
 $dst=imagecreatefromjpeg($background);
 for($i=0; $i<$b_x; $i++){
  for($j=0; $j<$b_y; $j++){
   $b_clr1=imagecolorsforindex($back, imagecolorat($back, $i-1, $j-1));\\ before 1 An array of pixel colors 
   $b_clr2=imagecolorsforindex($back, imagecolorat($back, $i, $j));\\ Retrieves the current color array 
   $r=intval($b_clr2["red"]+$degree*($b_clr2["red"]-$b_clr1["red"]));\\ To deepen 
   $g=intval($b_clr2["green"]+$degree*($b_clr2["green"]-$b_clr1["green"]));
   $b=intval($b_clr2["blue"]+$degree*($b_clr2["blue"]-$b_clr1["blue"]));
   $r=min(255, max($r, 0));// limit r In the range 0-255 between 
   $g=min(255, max($g, 0));
   $b=min(255, max($b, 0));
   if(($d_clr=imagecolorexact($dst, $r, $g, $b))==-1){// Is equal to the 1 Not in the color range 
    $d_clr=Imagecolorallocate($dst, $r, $g, $b);// create 1 A color 
   }
   imagesetpixel($dst, $i, $j, $d_clr);
  }
 }
 imagejpeg($dst, $save);
 imagedestroy($back);
 imagedestroy($dst);
}
sharp("./images/hee.jpg", 20, "./images/hee13.jpg");

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