Summary of PHP's various image processing function codes_PHP tutorial

1. Create image resources

imagecreatetruecolor(width,height);
imagecreatefromgif(picture name);
imagecreatefrompng(picture name);
imagecreatefromjpeg(picture name); draw various images imagegif (picture resource, save path) ;
imagepng()
imagejpeg();

2. Get image attributes

imagesx(res//width
imagesy(res//height
getimagesize(file path)
Returns an array with four cells. Index 0 contains the pixel value of the image width, index 1 contains The pixel value of the image height. Index 2 is a tag 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 are the same as the new IMAGETYPE constant added in PHP 4.3.0. Corresponding. Index 3 is a text string with the content "height="yyy" width="xxx"", which can be used directly for IMG tags
imagedestroy(picture resource);

3. Transparent processing

The transparent colors of PNG and jpeg are normal, only gif is abnormal

imagecolortransparent(resource image [,int color])//Set a color to be transparent

imagecolorstotal()
imagecolorforindex();

4. Cropping of pictures

imagecopyresized()

imagecopyresampled();

5. Add watermark (text, picture)

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

6. Image rotation

imagerotate(); // Image flip at specified angle

7. Flip of pictures

Flip along the X-axis along the Y-axis

8. Sharpening

imagecolorsforindex()

imagecolorat()

Draw graphics on pictures $img=imagecreatefromgif("./images/map.gif");

Copy code The code is as follows:

$red= imagecolorallocate($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);

Normal scaling of images

Copy code The code is as follows:

$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 the image and adjust it

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 scaling, no transparent color processing

Copy code The code is as follows:

function thumn($background, $width, $height, $newfile) {
list($s_w, $s_h)=getimagesize($background );//Get the original image height and width
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 processing

Copy code The code is as follows:

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)){//判断索引色
  $tran=imagecolorsforindex($img, $otsc);//索引颜色值

  $newt=imagecolorallocate($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");

图片裁剪

复制代码 代码如下:

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");

图片加水印

文字水印

复制代码 代码如下:

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", "细说PHP", 150, 250);

//图片水印
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);

图片旋转

复制代码 代码如下:

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

图片水平翻转垂直翻转

复制代码 代码如下:

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");

 图片锐化

复制代码 代码如下:

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));\Previous pixel color array
$b_clr2=imagecolorsforindex($back, imagecolorat($ back, $i, $j));\Get the current color array

$r=intval($b_clr2["red"]+$degree*($b_clr2["red"]-$b_clr1["red"]));\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 the range of r to 0-255
$g=min(255, max($g, 0));
$b=min(255, max($b, 0));

if(($d_clr=imagecolorexact($dst, $r, $g, $b))==-1){//Equal to 1 and not within the color range
$d_clr=Imagecolorallocate($dst, $ r, $g, $b);//Create 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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