Jag hinner tyvärr inte göra mer än att dela med mig av de funktioner som jag alltid använder och som funkar fint för mig...
För att skala en bild, anropa scalePic(infil, utfil, max X-storlek, max Y-storlek, kvalitet (0-100));
function scalePic($filnamn, $nyttfilnamn, $maxX, $maxY, $kvalitet = 75) {
$im = ImageCreateFromJPEG($filnamn);
$im_width=imageSX($im);
$im_height=imageSY($im);
if ($maxX > $maxY) {
$factor = $maxX/$im_width;
$new_width = $maxX;
$new_height = $im_height * $factor;
}
else {
$factor = $maxY/$im_width;
$new_width = $maxY;
$new_height = $im_height * $factor;
}
// resize
$new_im=ImageCreate($new_width,$new_height);
ImageCopyResampleBicubic($new_im,$im,0,0,0,0,$new_width,$new_height,$im_width,$im_height);
// output
Imagejpeg($new_im,$nyttfilnamn,$kvalitet); // quality 75
// cleanup
ImageDestroy($im);
ImageDestroy($new_im);
}
function ImageCopyResampleBicubic ($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h)
/*
port to PHP by John Jensen July 10 2001 -- original code (in C, for the PHP
GD Module) by [email]jernberg@fairytale.se[/email]
*/
{
for ($i = 0; $i < 256; $i++) { // get pallete. Is this algoritm correct?
$colors = ImageColorsForIndex ($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 = $scaleX / 2.0;
$scaleY2 = $scaleY / 2.0;
for ($j = $src_y; $j < $dst_h; $j++) {
$sY = $j * $scaleY;
for ($i = $src_x; $i < $dst_w; $i++) {
$sX = $i * $scaleX;
$c1 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, (int) $sX, (int) $sY + $scaleY2));
$c2 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, (int) $sX, (int) $sY));
$c3 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, (int) $sX + $scaleX2, (int) $sY + $scaleY2));
$c4 = ImageColorsForIndex ($src_img, ImageColorAt ($src_img, (int) $sX + $scaleX2, (int) $sY));
$red = (int) (($c1['red'] + $c2['red'] + $c3['red'] + $c4['red']) / 4);
$green = (int) (($c1['green'] + $c2['green'] + $c3['green'] + $c4['green']) / 4);
$blue = (int) (($c1['blue'] + $c2['blue'] + $c3['blue'] + $c4['blue']) / 4);
$color = ImageColorClosest ($dst_img, $red, $green, $blue);
ImageSetPixel ($dst_img, $i + $dst_x, $j + $dst_y, $color);
}
}
}
