Question about batch processing, and kudos

[flashape]

First off, I have been messing around with the IMagick extension, and from what I have seen so far I am loving it. THANK YOU so much for that to whoever is responsible.

So, I have a question about batch processing a folder of images. My situation is that I have a folder with about 1,000 jpgs in it. I need to composite a small png graphic in each frame. The catch is that the png's x,y,width,height, and rotation values are going to be different on every frame.

Currently what I have works fine, but I don't feel like it is the most efficient. Here is what the php code looks like:

Code: Select all

$num = count($positions);
		
		$headFile = 'temp/head.png';

		$res='';
		for($i = 1; $i<$num; $i++){
			$pos = $positions[$i-1];
			
			
			$frame = new Imagick('temp/frame'.$i.'.png');
			
			if( $pos['valid']){
			
				$w = $pos['width'];
				$h = $pos['height'];
			
				$x = ceil( $pos['x'] );
				$y = ceil( $pos['y'] - 10 );
			
				$rot = ceil( $pos['rotation'] );
				
				$head = new Imagick($headFile);
				
				
				$head->resizeImage($w ,$h,Imagick::FILTER_LANCZOS,1);
				$head->rotateImage('transparent',$rot);
				$frame->compositeImage($head, $head->getImageCompose(), $x, $y);
			}
			
			
			$frame->writeImage('output/frame'.$i.'.jpg');
			
		}

The idea is:
-loop through an array of objects which contains info on how to position the png on each frame
- open the background image ($frame)
- read the head image
- compose the head onto the frame
- save the composed image as a new file

As you can see, I am re-creating the $head file every time through the loop, because it will be modified every time it runs. Is there a more efficient way to do this? Or a better way to do all of it?

[mkoppanen]

Something like this maybe:

Changes:
a) read head image only once and clone it when needed
b) use thumbnailImage instead resizeImage (strips image profiles and comments)
c) Use Imagick::COMPOSITE_OVER constant instead of fetching Composite operator every time
d) Use the same frame object on each iteration, just clean it after use

Code: Select all

<?php

$frame = new Imagick();
$head = new Imagick( 'temp/frame' . $i . '.png' );

$num = count($positions);
$res='';

for ( $i = 1; $i < $num; $i++ )
{
	$pos = $positions[$i-1];
	$frame->readImage( 'temp/frame' . $i . '.png' );
	
	if ( $pos['valid'])
	{
		$w = $pos['width'];
		$h = $pos['height'];
	
		$x = ceil( $pos['x'] );
		$y = ceil( $pos['y'] - 10 );
	
		$rot = ceil( $pos['rotation'] );
	
		$tmpHead = $head->clone();
	
		$tmpHead->thumbnailImage( $w, $h );
		
		$tmpHead->rotateImage( 'transparent', $rot );
		
		$frame->compositeImage( $tmpHead, Imagick::COMPOSITE_OVER, $x, $y );
	
		$tmpHead->destroy();
	}
	
	$frame->writeImage( 'output/frame'.$i.'.jpg' );
	$frame->clear();
}

[flashape]

thanks, that helped a lot, cut about 1/3 of processing time.