Don't listen to the blue meanies, here are some functions for you, and welcome to using PHP! 🙂
Use it like this:
scalePic($filename, $newfilename, $maxX, $maxY, $quality)
where
$filename is the filename and path of the JPEG-image you want to scale
$newfilename is the filename and path of the finished scaled image
$maxX is the max width of the new picture
$maxY is the max height of the new picture
$quality is the JPEG-quality of the new picture (0-100).
Example:
scalepic("/tmp/image.jpg", "/tmp/scaled.jpg", 320, 240, 75);
this example will open /tmp/image.jpg and scale it to max 320x240 pixels and save it with 75% JPEG-quality at /tmp/scaled.jpg
Hope you find it useful!
//Mans
function scalePic($filename, $newfilname, $maxX, $maxY, $quality = 75) {
$im = ImageCreateFromJPEG($filename);
$im_width=imageSX($im);
$im_height=imageSY($im);
$new_height = $maxY;
$new_width = $maxX;
// resize
$new_im=ImageCreateTrueColor($new_width,$new_height);
ImageCopyResampleBicubic($new_im,$im,0,0,0,0,$new_width,$new_height,$im_width,$im_height);
// output
Imagejpeg($new_im,$newfilename,$quality); // 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);
}
}
}
