note 44490 deleted from function.imagecopyresampled by cmb
| From: | cmb@php.net | Date: | Sun, 09 Oct 2016 11:41:11 +0000 |
| Subject: | note 44490 deleted from function.imagecopyresampled by cmb | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-206817@lists.php.net to get a copy of this message | ||
Note Submitter: ron at korving dot demon dot nl
----
This Bicubic resample algorithm is based on the one Scott posted earlier, only this one is about 50%
faster for truecolor images and about 10% faster for palette images.
<?
function imageCopyResampleBicubic($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w,
$dst_h, $src_w, $src_h)
{
$scaleX = ($src_w - 1) / $dst_w;
$scaleY = ($src_h - 1) / $dst_h;
$scaleX2 = $scaleX / 2.0;
$scaleY2 = $scaleY / 2.0;
$tc = imageistruecolor($src_img);
for ($y = $src_y; $y < $src_y + $dst_h; $y++)
{
$sY = $y * $scaleY;
$siY = (int) $sY;
$siY2 = (int) $sY + $scaleY2;
for ($x = $src_x; $x < $src_x + $dst_w; $x++)
{
$sX = $x * $scaleX;
$siX = (int) $sX;
$siX2 = (int) $sX + $scaleX2;
if ($tc)
{
$c1 = imagecolorat($src_img, $siX, $siY2);
$c2 = imagecolorat($src_img, $siX, $siY);
$c3 = imagecolorat($src_img, $siX2, $siY2);
$c4 = imagecolorat($src_img, $siX2, $siY);
$r = (($c1 + $c2 + $c3 + $c4) >> 2) & 0xFF0000;
$g = ((($c1 & 0xFF00) + ($c2 & 0xFF00) + ($c3 & 0xFF00) + ($c4 & 0xFF00))
>> 2) & 0xFF00;
$b = ((($c1 & 0xFF) + ($c2 & 0xFF) + ($c3 & 0xFF) + ($c4 & 0xFF))
>> 2);
imagesetpixel($dst_img, $dst_x + $x - $src_x, $dst_y + $y - $src_y, $r+$g+$b);
}
else
{
$c1 = imagecolorsforindex($src_img, imagecolorat($src_img, $siX, $siY2));
$c2 = imagecolorsforindex($src_img, imagecolorat($src_img, $siX, $siY));
$c3 = imagecolorsforindex($src_img, imagecolorat($src_img, $siX2, $siY2));
$c4 = imagecolorsforindex($src_img, imagecolorat($src_img, $siX2, $siY));
$r = ($c1['red'] + $c2['red'] + $c3['red'] +
$c4['red'] ) << 14;
$g = ($c1['green'] + $c2['green'] + $c3['green'] +
$c4['green']) << 6;
$b = ($c1['blue'] + $c2['blue'] + $c3['blue'] +
$c4['blue'] ) >> 2;
imagesetpixel($dst_img, $dst_x + $x - $src_x, $dst_y + $y - $src_y, $r+$g+$b);
}
}
}
}
?>