note 51052 added to ref.image

.::SHARPEN YOUR IMAGES::. ---by Alex R. Austin I became aware that there is just NO image sharpening in PHP4. Thus, writing code for my photo album I found that using resize function "imagecopyresampled" would blur my thumbnails. After not finding any way to sharpen my thumbs I wrote this code. Please keep in mind that PHP is not C++ and speed is somewhat slow. I have optimised my code as far as I could. If you can make it faster be my guest. The 800x600 image gets sharpened on my machine in 9 seconds. A 200x150 thumbnail takes only half a second. Thus, it is not that bad. <? $filename='test.jpg'; list($width, $height) = getimagesize($filename); $img = imagecreatefromjpeg($filename); $pix=array(); //get all color values off the image for($hc=0; $hc<$height; ++$hc){ for($wc=0; $wc<$width; ++$wc){ $rgb = ImageColorAt($img, $wc, $hc); $pix[$hc][$wc][0]= $rgb >> 16; $pix[$hc][$wc][1]= $rgb >> 8 & 255; $pix[$hc][$wc][2]= $rgb & 255; } } //sharpen with upper and left pixels $height--; $width--; for($hc=1; $hc<$height; ++$hc){ $r5=$pix[$hc][0][0]; $g5=$pix[$hc][0][1]; $b5=$pix[$hc][0][2]; $hcc=$hc-1; for($wc=1; $wc<$width; ++$wc){ $r=-($pix[$hcc][$wc][0]); $g=-($pix[$hcc][$wc][1]); $b=-($pix[$hcc][$wc][2]); $r-=$r5+$r5; $g-=$g5+$g5; $b-=$b5+$b5; $r5=$pix[$hc][$wc][0]; $g5=$pix[$hc][$wc][1]; $b5=$pix[$hc][$wc][2]; $r+=$r5*5; $g+=$g5*5; $b+=$b5*5; $r*=.5; $g*=.5; $b*=.5; //here the value of 0.75 is like 75% of sharpening effect //Change if you need it to 0.01 to 1.00 or so //Zero would be NO effect //1.00 would be somewhat grainy $r=(($r-$r5)*.75)+$r5; $g=(($g-$g5)*.75)+$g5; $b=(($b-$b5)*.75)+$b5; if ($r<0) $r=0; elseif ($r>255) $r=255; if ($g<0) $g=0; elseif ($g>255) $g=255; if ($b<0) $b=0; elseif ($b>255) $b=255; imagesetpixel($img,$wc,$hc,($r << 16)|($g << 8)|$b); } } //save pic imageinterlace($img,1); imagejpeg($img,'test_save.jpg',99); imagedestroy($img); ?> ---- Manual Page -- http://www.php.net/manual/en/ref.image.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+51052 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+51052&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+51052&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+51052&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+51052&report=yes&reason=useless Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+51052&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+51052&report=yes Search -- http://master.php.net/manage/user-notes.php