Php image scaling implementation

Php image scaling implementation

This article mainly introduces the php image scaling implementation method. For more information, see

Php basic exercises-Image Scaling:

 

 

The Code is as follows:

<? Php

/**

* Image zoom.

*/

Function imageZoom ($ filename, $ w, $ h ){

/* Arguments meaning */

/* $ Filename: the source of the name */

/* $ W: you want get the image's width */

/* $ H: you want get the imgage's height */

$ Arr = getimagesize ($ filename );

$ Src_w = $ arr [0];

$ Src_h = $ arr [1];

$ Src_t = $ arr [2];

/* 1 = GIF, 2 = JPG, 3 = PNG, 4 = SWF, 5 = PSD, 6 = BMP, 7 = TIFF (intel byte order ),

= TIFF (motorola byte order), 9 = JPC, 10 = JP2, 11 = JPX, 12 = JB2, 13 = SWC,

= IFF, 15 = WBMP, 16 = XBM */

$ Src_m = $ arr ['mime '];

 

$ Src_img = imagecreatefromjpeg ($ filename );

 

If ($ w/$ src_w)> ($ h/$ src_h )){

$ Bili = $ h/$ src_h;

} Else {

$ Bili = $ w/$ src_h;

}

$ Dst_w = $ src_w * $ bili;

$ Dst_h = $ src_h * $ bili;

$ Dst_img = imagecreatetruecolor ($ dst_w, $ dst_h );

 

Imagecopyresampled ($ dst_img, $ src_img, 0, 0, 0, $ dst_w, $ dst_h, $ src_w, $ src_h );

 

Header ("content-type: {$ src_m }");

 

Switch ($ src_t ){

Case 1:

$ Imgout = "imagegif ";

Break;

Case 2:

$ Imgout = "imagejpeg ";

Break;

Case 3:

$ Imgout = "imagepng ";

Break;

Default:

Echo "The type was wrong! ";

Break;

}

 

$ Dst_filename = "s _". $ filename;

$ Imgout ($ dst_img, $ dst_filename );

 

Imagedestroy ($ dst_img );

}

$ Filename = 'gg.jpg ';

ImageZoom ($ filename, 100,200 );

 

 

 

Core: <1> pay attention to how the zoom ratio is obtained. Although the image may be slightly different from the Expected One, the zoom ratio is guaranteed at least.

 

<2> type control.