thumbnail resizing

[wendu]

hey

 

I'm trying to make a thumbnail of an image and I already have the code working to create the thumbnail

 

however I need a way to calculate values so that respecting the aspect ratio I can make the thumbnail either 150 pixels wide or high but neither can go over 150, and the aspect ratio needs to stay the same

 

thanks!! <33

[redarrow]

look into gd commands bro....

 

 

[ignace]

$maxWidth = 150;
$maxHeight = 150;

list($width, $height) = getimagesize('path/to/image');

$ratio = 1;
if ($width > $maxWidth) {
    $ratio = $maxWidth / $width;
} else if ($height > $maxHeight) {
    $ratio = $maxHeight / $height;
}

$newWidth = $width * $ratio;
$newHeight = $height * $ratio;

[wendu]

$maxWidth = 150;
$maxHeight = 150;

list($width, $height) = getimagesize('path/to/image');

$ratio = 1;
if ($width > $maxWidth) {
    $ratio = $maxWidth / $width;
} else if ($height > $maxHeight) {
    $ratio = $maxHeight / $height;
}

$newWidth = $width * $ratio;
$newHeight = $height * $ratio;

 

yes you've given me this piece of code however it does not work if both the width and the hight are the same

[wendu]

 

yes you've given me this piece of code however it does not work if both the width and the hight are the same

 

any help?

[Alex]

An Image class that I wrote quickly has the ability to do exactly what you want (and a lot more).

 

here's the class:

 

class Image
{
var $image, $ext, $file;
public function __construct($im=NULL)
{
	define('CENTER', 0, true);
	define('CENTER_LEFT', 1, true);
	define('CENTER_RIGHT', 2, true);
	define('TOP_CENTER', 3, true);
	define('TOP_LEFT', 4, true);
	define('TOP_RIGHT', 5, true);
	define('BOTTOM_CENTER', 6, true);
	define('BOTTOM_LEFT', 7, true);
	define('BOTTOM_RIGHT', 8, true);

	if(empty($im)) return true;
	$info = @getimagesize($im);
	$backtrace = debug_backtrace();
	if(!$info)
		return die('<b>Fatal error:</b> \'' . $im . '\' is not a valid image resource on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	$ex = explode('/', $info['mime']);
	$this->ext = $ex[1];
	$func = 'imagecreatefrom' . $this->ext;
	$this->image = @$func($im);
	$this->file = $im;
	return true;
}
public function setImage($im)
{
	$info = @getimagesize($this->file);
	$backtrace = debug_backtrace();
	if(!$info)
		return die('<b>Fatal error:</b> \'' . $im . '\' is not a valid image resource on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	$ex = explode('/', $info['mime']);
	$this->ext = $ex[1];
	$func = 'imagecreatefrom' . $this->ext;
	$this->image = @$func($im);
	$this->file = $im;
	return true;
}
public function resize($width, $height, $porportional=FALSE, $percent=NULL, $max=NULL)
{
	$backtrace = debug_backtrace();
	if(empty($this->image)) return die('<b>Fatal error:</b> Invalid call to Image()->resize, no image is set on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	$info = Array(imagesx($this->image), imagesy($this->image));
	if($porportional)
	{
		if(empty($max) && empty($percent)) return false;
		if(empty($max))
		{
			$new_width = $info[0] * ($percent/100);
			$new_height = $info[1] * ($percent/100);
		}
		else
		{
			if($info[0] < $max && $info[1] < $max) return false;
			$new_width = ($info[0] > $info[1]) ? $max : ($info[0]/$info[1]) * $max;
			$new_height = ($info[0] > $info[1]) ? ($info[1]/$info[0]) * $max : $max;
		}
	}
	else
	{
		$new_width = $width;
		$new_height = $height;
	}
	$new_image = imagecreatetruecolor($new_width, $new_height);
	imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $new_width, $new_height, $info[0], $info[1]);
	$this->image = $new_image;
	return true;
}
public function crop($width, $height, $x, $y, $position=NULL)
{
	$backtrace = debug_backtrace();
	if(empty($this->image)) return die('<b>Fatal error:</b> Invalid call to Image()->crop, no image is set on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	$info = Array(imagesx($this->image), imagesy($this->image));
	if($width > $info[0] || $height > $info[1]) return false;
	if(!empty($position) && $position >= 0 && $position <= 
	{
		switch($position)
		{
			case CENTER:
				$x = ($info[0] - $width)/2;
				$y = ($info[1] - $height)/2;
			break;
			case CENTER_LEFT:
				$x = 0;
				$y = ($info[1] - $height)/2;
			break;
			case CENTER_RIGHT:
				$x = ($info[0] - $height);
				$y = ($info[1] - $height)/2;
			break;
			case TOP_CENTER:
				$x = ($info[0] - $width)/2;
				$y = 0;
			break;
			case TOP_LEFT:
				$x = 0;
				$y = 0;
			break;
			case TOP_RIGHT:
				$x = ($info[0] - $width);
				$y = 0;
			break;
			case BOTTOM_CENTER:
				$x = ($info[0] - $width)/2;
				$y = ($info[1] - $height);
			break;
			case BOTTOM_LEFT:
				$x = 0;
				$y = ($info[1] - $height);
			break;
			case BOTTOM_RIGHT:
				$x = ($info[0] - $width);
				$y = ($info[1] - $height);
			break;
			default:
				return false;
			break;
		}
	}
	$new_image = imagecreatetruecolor($width, $height);
	imagecopyresampled($new_image, $this->image, 0, 0, $x, $y, $width, $height, $width, $height);
	$this->image = $new_image;
	return true;
}
public function save($loc, $compression=0)
{
	$backtrace = debug_backtrace();
	if(empty($this->image)) return die('<b>Fatal error:</b> Invalid call to Image()->save, no image is set on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	$func = 'image' . $this->ext;
	return $func($this->image, $loc, $compression);
}
public function output()
{
	$backtrace = debug_backtrace();
	if(empty($this->image)) return die('<b>Fatal error:</b> Invalid call to Image()->output, no image is set on <b>line ' . $backtrace[0]['line'] . ' [' . $backtrace[0]['file'] . ']</b>');
	header('Content-type: image/' . $this->ext);
	$func = 'image' . $this->ext;
	$func($this->image);
}
}

 

You're gonna wanna do something like this:

 

//Include my class
$image = new Image('path/to/image');
$image->resize(null, null, true, null, 150);
$image->save('path/to/new/location.ext');

[ignace]

Alex the class you specified is wrong everytime you create a new instance of the class you'd get an error.

 

new Image('bla');
new Image('bla');// cannot redefine CENTER already defined in ..

 

Plus if you are writing for PHP4 (altough since 5.3.0 most hosts are now switching to PHP5) then keep it PHP4 or if you want to make use of all the OOP features PHP5 gives you then change your class for PHP5.

 

Thus either:

 

define('CENTER', 0, true);
..

class Image {
    var $image, $ext, $file;
    function Image($im = null) {
    ..

 

or:

 

class Image {
    const CENTER = 0;
    ..
    
    public $image, $ext, $file;//altough you should consider private instead of public
    public function __construct($im = null) {
    ..

[Alex]

Thanks. I never even thought about the define problem.

 

There are some other things in there that could be optimized as well, but it was written fast and I never went back to clean it up.