PHP/GD - Cropping and Resizing Images
- by Alix Axel
I've coded a function that crops an image to a given aspect ratio and finally then resizes it and outputs it as JPG:
<?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;
}
/*
How can I skip (join) this operation
with the one in the Resize Section?
*/
$result = ImageCreateTrueColor($width, $height);
if (is_resource($result) === true)
{
ImageSaveAlpha($result, true);
ImageAlphaBlending($result, false);
ImageFill($result, 0, 0, ImageColorAllocateAlpha($result, 255, 255, 255, 127));
ImageCopyResampled($result, $image, 0, 0, $x, $y, $width, $height, $width, $height);
$image = $result;
}
}
/*
Resize Section
*/
if (is_null($size) === true)
{
$size = array(imagesx($image), imagesy($image));
}
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] * imagesx($image) / imagesy($image));
}
else if ((empty($size[1]) === true) || (is_numeric($size[1]) === false))
{
$size[1] = round($size[0] * imagesy($image) / imagesx($image));
}
}
}
$result = ImageCreateTrueColor($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, 0, 0, $size[0], $size[1], imagesx($image), imagesy($image));
header('Content-Type: image/jpeg');
ImageInterlace($result, true);
ImageJPEG($result, null, 90);
}
}
return false;
}
?>
The function works as expected but I'm creating a non-required GD image resource, how can I fix it? I've tried joining both calls but I must be doing some miscalculations.
<?php
/*
Usage Examples
*/
Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '1:1', '600x');
Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:1', '600x');
Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:', '250x300');
?>
Any help is greatly appreciated, thanks.
