Sharpen images in PHP

<?

// Read 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

Function getimagetype ($ filename) {return ($ imginfo = @ getimagesize ($ filename ))! = NULL? $ Imginfo [2]: NULL );}

// Sharpen the image

// $ Scr_im: image resource handle, $ degree: Sharpen

Function sharp (& $ src_im, & $ dst_im, $ degree)

{

$ Src_x = imagesx ($ src_im );

$ Src_y = imagesy ($ src_im );

// $ Dst_im = imagecreate ($ src_x, $ src_y );

// Imagecopy ($ dst_im, $ src_im, 0, 0, 0, 0, $ src_x, $ src_y );

$ CNT = 0;

For ($ x = 1; $ x <$ src_x; $ X ++)

For ($ y = 1; $ Y <$ src_y; $ y ++)

{

$ Src_clr1 = imagecolorsforindex ($ src_im, imagecolorat ($ src_im, $ X-1, $ Y-1 ));

$ Src_clr2 = imagecolorsforindex ($ src_im, imagecolorat ($ src_im, $ X, $ y ));

$ R = intval ($ src_clr2 ["red"] + $ degree * ($ src_clr2 ["red"]-$ src_clr1 ["red"]);

$ G = intval ($ src_clr2 ["green"] + $ degree * ($ src_clr2 ["green"]-$ src_clr1 ["green"]);

$ B = intval ($ src_clr2 ["blue"] + $ degree * ($ src_clr2 ["blue"]-$ src_clr1 ["blue"]);

$ R = min (255, max ($ R, 0 ));

$ G = min (255, max ($ g, 0 ));

$ B = min (255, max ($ B, 0 ));

// Echo "R: $ R, G: $ G, B: $ B <br/> ";

If ($ dst_clr = imagecolorexact ($ dst_im, $ R, $ g, $ B) =-1)

$ Dst_clr = imagecolorallocate ($ dst_im, $ R, $ g, $ B );

$ CNT ++;

If ($ dst_clr =-1) Die ("color allocate faile at $ X, $ Y ($ CNT ).");

Imagesetpixel ($ dst_im, $ X, $ y, $ dst_clr );

}

Return $ dst_im;

}

$ Imagefunctions = array ("imagecreatefromwbmp", "imagecreatefromgif", "imagecreatefromjpeg", "imagecreatefrompng ");

If (! Empty ($ _ post ["imagename"])

{

Set_time_limit (10*60 );

If ($ imagetype = getimagetype ($ _ post ["imagename"]) = false)

Die ("the specified file does not exist or is not a valid image or does not support the type! ");

If ($ imagetype = 6) $ imagetype = 0;

If ($ imagetype> 3) Die ("unsupported image type! ");

$ Im1 = $ imagefunctions [$ imagetype] ($ _ post ["imagename"]);

$ IM2 = $ imagefunctions [$ imagetype] ($ _ post ["imagename"]);

// Print_r (imagecolorsforindex ($ im, imagecolorat ($ im, 10, 10 )));

Sharp ($ im1, $ IM2, $ _ post ["degree"]);

Header ("Content-Type: image/PNG ");

Imagepng ($ IM2 );

Imagedestroy ($ im1 );

Imagedestroy ($ IM2 );

}

?>

<Form name = "formname" Action = "" method = "Post">

Enter the local path or URL of the image: <br/>

<Input name = "imagename" type = "text" value = "<? =_ _ Post ["imagename"]?> "Size = 32> <br/>

Sharpen degree (for example, 0.6, 3.0): <br/>

<Input name = "degree" type = "text" value = "<? =_ _ Post ["degree"]?> "> <Br/>

<Input type = "Submit" value = "Submit">

</Form>

Changed the value and saved a $ IM:

Function sharp2 (& $ im, $ degree)

{

$ CNT = 0;

For ($ x = imagesx ($ IM)-1; $ x> 0; $ X --)

For ($ Y = imagesy ($ IM)-1; $ Y> 0; $ y --)

{

$ Clr1 = imagecolorsforindex ($ im, imagecolorat ($ im, $ X-1, $ Y-1 ));

$ Clr2 = imagecolorsforindex ($ im, imagecolorat ($ im, $ X, $ y ));

$ R = intval ($ clr2 ["red"] + $ degree * ($ clr2 ["red"]-$ clr1 ["red"]);

$ G = intval ($ clr2 ["green"] + $ degree * ($ clr2 ["green"]-$ clr1 ["green"]);

$ B = intval ($ clr2 ["blue"] + $ degree * ($ clr2 ["blue"]-$ clr1 ["blue"]);

$ R = min (255, max ($ R, 0 ));

$ G = min (255, max ($ g, 0 ));

$ B = min (255, max ($ B, 0 ));

// Echo "R: $ R, G: $ G, B: $ B <br> ";

If ($ new_clr = imagecolorexact ($ im, $ R, $ g, $ B) =-1)

$ New_clr = imagecolorallocate ($ im, $ R, $ g, $ B );

$ CNT ++;

If ($ new_clr =-1) Die ("color allocate faile at $ X, $ Y ($ CNT ).");

Imagesetpixel ($ im, $ X, $ y, $ new_clr );

}

}