note 20905 deleted from function.imagecopyresized by aidan
| From: | aidan@php.net | Date: | Mon, 04 Oct 2004 09:40:35 +0000 |
| Subject: | note 20905 deleted from function.imagecopyresized by aidan | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-77927@lists.php.net to get a copy of this message | ||
Note Submitter: rze at counter-strike dot net
----
I have added various optimization updates to my PHP bicubic function, along with a few fixes. Thanks
to scott@pawprint.net for pointing out that src_x/y were being factored into the placement on the
dst_img.
function ImageCopyResampleBicubic (&$dst_img, &$src_img, $dst_x, $dst_y, $src_x, $src_y,
$dst_w, $dst_h, $src_w, $src_h)
/*
port to PHP by John Jensen July 10 2001 (updated 4/21/02) -- original code (in C, for the PHP GD
Module) by jernberg@fairytale.se
*/
{
$palsize = ImageColorsTotal ($src_img);
for ($i = 0; $i < $palsize; $i++) { // get palette.
$colors = ImageColorsForIndex ($src_img, $i);
ImageColorAllocate ($dst_img, $colors['red'], $colors['green'],
$colors['blue']);
}
$scaleX = ($src_w - 1) / $dst_w;
$scaleY = ($src_h - 1) / $dst_h;
$scaleX2 = (int) ($scaleX / 2);
$scaleY2 = (int) ($scaleY / 2);
for ($j = $src_y; $j < $dst_h; $j++) {
$sY = (int) ($j * $scaleY);
$y13 = $sY + $scaleY2;
for ($i = $src_x; $i < $dst_w; $i++) {
$sX = (int) ($i * $scaleX);
$x34 = $sX + $scaleX2;
$color1 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, $sX, $y13));
$color2 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, $sX, $sY));
$color3 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, $x34, $y13));
$color4 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, $x34, $sY));
$red = ($color1['red'] + $color2['red'] + $color3['red'] +
$color4['red']) / 4;
$green = ($color1['green'] + $color2['green'] + $color3['green'] +
$color4['green']) / 4;
$blue = ($color1['blue'] + $color2['blue'] + $color3['blue'] +
$color4['blue']) / 4;
ImageSetPixel ($dst_img, $i + $dst_x - $src_x, $j + $dst_y - $src_y, ImageColorClosest ($dst_img,
$red, $green, $blue));
}
}
}
It saves a few trivial computations, but in a function like this, it might actually save a few
milliseconds off the exec time. Either way, the palette and src_x/y fixes make the update worth
using.