Summary of various php image processing function code

This article mainly introduces php's image processing implementation code, including scaling, cropping, scaling, flip, rotating, transparent, sharpening, and other image operations. For more information, see I. create image resources

Imagecreatetruecolor (width, height );
Imagecreatefromgif (image name );
Imagecreatefrompng (image name );
Imagecreatefromjpeg (image name); draw various image imagegif (image resource, save path );
Imagepng ()
Imagejpeg ();

II. retrieving image attributes

Imagesx (res // width
Imagesy (res // height
Getimagesize (file path)
Returns an array with four units. 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 mark of 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 newly added IMAGETYPE constant in PHP 4.3.0. Index 3 is a text string with the content "height =" yyy "width =" xxx "and can be directly used for IMG marking.
Destroy Image resources
Imagedestroy (image resources );

3. transparent processing

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

Imagecolortransparent (resource image [, int color]) // sets a color to transparent.
Imagecolorstotal ()
Imagecolorforindex ();

IV. image cropping

Imagecopyresized ()
Imagecopyresampled ();

5. add watermarks (text and images)

String Encoding and conversion string iconv (string $ in_charset, string $ out_charset, string $ str)

VI. rotating images

Imagerotate (); // specifies the Image flip angle

VII. Image flip

Flip along x axis along y axis

8. sharpen

Imagecolorsforindex ()

Imagecolorat ()

Image $ img = imagecreatefromgif ("./images/map.gif ");

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 image scaling

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 and adjust part of the image

Imagecopyresized ($ new, $ img, 0, 0, 0, $ n_w, $ n_h, $ width, $ height );
// Output new image and save it

Imagejpeg ($ new, "./images/hee2.jpg ");

Imagedestroy ($ new );
Imagedestroy ($ img );

Proportional scaling of images, not processing transparent colors

The code is as follows:

Function thumn ($ background, $ width, $ height, $ newfile ){
List ($ s_w, $ s_h) = getimagesize ($ background); // Obtain 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 processing

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) {// you can determine the 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 ");

Crop Images

The code is as follows:

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 ");

Add watermarks to images

Text watermark

The code is as follows:

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", "PHP", 150,250 );

// Image watermark
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

The code is as follows:

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

Horizontal flip vertical flip

The code is as follows:

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

The code is as follows:

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); \ retrieves 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); // limits the r range to 0.
$ G = min (255, max ($ g, 0 ));
$ B = min (255, max ($ B, 0 ));

If ($ d_clr = imagecolorexact ($ dst, $ r, $ g, $ B) =-1) {// equal to 1 is not in 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 ");