Resize image with ratio using PHP

Say I've got some squar开发者_运维问答e images which I want to resize to rectangle images with the ratio 16:9. What is the best way to do it using PHP?

you could use imagecopyresampled ( resource $dst_image , resource $src_image , int $dst_x , int $dst_y , int $src_x , int $src_y , int $dst_w , int $dst_h , int $src_w , int $src_h )

more at http://us2.php.net/imagecopyresampled

Try this... Not Using GD but i think it will work for u.

<?php
function Image($image, $crop = null, $size = null) {
$image = ImageCreateFromString(file_get_contents($image));

 if (is_resource($image) === true) {
$x = 0;
$y = 0;
$width = imagesx($image);
$height = imagesy($image);

/*
CROP (Aspect Ratio) Section
*/

if (is_null($crop) === true) {
    $crop = array($width, $height);
} else {
    $crop = array_filter(explode(':', $crop));

    if (empty($crop) === true) {
            $crop = array($width, $height);
    } else {
        if ((empty($crop[0]) === true) || (is_numeric($crop[0]) === false)) {
                $crop[0] = $crop[1];
        } else if ((empty($crop[1]) === true) || (is_numeric($crop[1]) === false)) {
                $crop[1] = $crop[0];
        }
    }

    $ratio = array(0 => $width / $height, 1 => $crop[0] / $crop[1]);

    if ($ratio[0] > $ratio[1]) {
        $width = $height * $ratio[1];
        $x = (imagesx($image) - $width) / 2;
    }

    else if ($ratio[0] < $ratio[1]) {
        $height = $width / $ratio[1];
        $y = (imagesy($image) - $height) / 2;
    }

}

/*
Resize Section
*/

if (is_null($size) === true) {
    $size = array($width, $height);
}

else {
    $size = array_filter(explode('x', $size));

    if (empty($size) === true) {
            $size = array(imagesx($image), imagesy($image));
    } else {
        if ((empty($size[0]) === true) || (is_numeric($size[0]) === false)) {
                $size[0] = round($size[1] * $width / $height);
        } else if ((empty($size[1]) === true) || (is_numeric($size[1]) === false)) {
                $size[1] = round($size[0] * $height / $width);
        }
    }
}

  $result = ImageCreateTrueColor($size[0], $size[1]);

if (is_resource($result) === true) {
    ImageSaveAlpha($result, true);
    ImageAlphaBlending($result, true);
    ImageFill($result, 0, 0, ImageColorAllocate($result, 255, 255, 255));
    ImageCopyResampled($result, $image, 0, 0, $x, $y, $size[0], $size[1], $width, $height);

    ImageInterlace($result, true);
    ImageJPEG($result, null, 90);
}
}

return false;
 }

header('Content-Type: image/jpeg');
 Image('image.jpg', '2:1', '1200x');

?>