[SOLVED] Aspect ratio

[shage]

In url it has &h=??? the height will be set by user, but should have a max of say 300, the pic will be 300 by whatever so that if they pick to big it will just use the standard pic size, how would i go about keeping the aspect ratio, ive looked but no luck

[Wildbug]

Use algebra to solve for the new width.

 

o = original, n = new, w = width, h = height

 

ow/oh = nw/nh,

(nh*ow)/oh = nw

[trq]

There is an example of resizing by percentage in the man page for imagecopyresized, should be pretty easy to do from there.

[Carterhost]

It's not foolproof, but if you just specify the height in the image tag (i.e. no width) then the aspect ratio is usually kept...

[cooldude832]

this is what i use to resample on the fly with out GD its pretty good (getImageSize is it)

<?php
	$image = "myimage,/pg";
	$tempimg = 	getImageSize($image);
	$size = $tempimg[3];
	$size = explode("\"",$size);
	$width = $size[1];
	$height = $size[3];
while($height > $maxheight || $width > $maxwidth)
	{
		$width = .99*$width;
		$height = .99*$height;
	}
echo "<img src=\"myimage.jpg\" width=\"".$width."\" height=\"."$height."\" />";
?>