Thumbnails erstellen

[Harry]

Holladiri

ich möchte über php automatisch thumbnails erzeugen lassen - allerdings bin ich mit der qualität nicht zufrieden.

In den Benutzerkommentaren zu imagecopyresized() http://www.php.net/manual/en/function.imagecopyresized.php findest Du eine Funktion für bikubische Grössenänderung:

------------------------------------------------
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 [e-mail]
*/
{
 $palsize = ImageColorsTotal ($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));
  }
 }
}
------------------------------------------------

Ciao,

Harry