note 29197 added to function.imagecopyresized

From: Date: Wed, 05 Feb 2003 21:17:01 +0000
Subject: note 29197 added to function.imagecopyresized
Groups: php.notes 
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re: numerical filtering/imagecopyresamplebicubic it should be noted that the imagecopyresamplebicubic() function posted above is not doing true bicubic resampling. Instead of averaging all pixels contained within the area being resized, only the corner points of that area are averaged. This is not a huge deal because it still looks nicer than imagecopyresized(). It's likely that true bicubic resampling would take too long for general php uses. I don't understand the numeric filtering mentioned in other posts, but improvements to the math in imagecopyresamplebicubic() that kept the speed fast would be appreciated. also it's worth noting that the function above always assumes it's being used for downsampling a larger image to a smaller one. This is probably not a big deal because 99.9% of the time people will be using the function to create thumbnails, but the point is that under certain circumstances the function will behave unpredictably, and is not a general-use function like the GD library's imagecopyresized(). I personally don't have time to correct the function right now, but if i get it done in the future i will post it. -- http://www.php.net/manual/en/function.imagecopyresized.php http://master.php.net/manage/user-notes.php?action=edit+29197 http://master.php.net/manage/user-notes.php?action=delete+29197 http://master.php.net/manage/user-notes.php?action=reject+29197

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