[RESOLVED] keeping ratio image while resizing...

[coldwerturkey]

Guys,

I'm going to be honest, I've had a little to drink and I cannot put this together.

I have a said original image of 604x402 pixels.

I use the following to find the new dimensions of a large thumb, while trying to maintain the ratio;

$new_w = 480;
$new_h = 360;

//...

if ($old_x > $old_y) {
	$thumb_w=$new_w;
	$thumb_h=$old_y*($new_h/$old_x);
}
if ($old_x < $old_y) {
	$thumb_w=$old_x*($new_w/$old_y);
	$thumb_h=$new_h;
}
if ($old_x == $old_y) {
	$thumb_w=$new_w;
	$thumb_h=$new_h;
}

//...

and get an improper distorted image of 480x239 pixels...

it should be right around 480 by 320 pixels to maintain the ratio,

what's wrong with my algorithm?

[jazz_snob]

The ratio remains unchanged:

nw/ht = ow/oh

where

new width = nw
new height = nh
old width = ow
old height = oh

Question is, how are you doing this conversion? I use "convert" which means I do an exec() to invoke the convert binary and resize the image to the target size. Its really easy so if its on your server, you're luck 😉

http://www.imagemagick.org/script/convert.php

[NogDog]

I've done something like this in the past:

$ratio = (($old_x / $old_y) > ($new_w / $new_h)) ? $new_w / $old_x : $new_h / $old_y;
$thumb_w = (round($ratio * $old_x));
$thumb_h = ($ound($ratio * $old_y));

[coldwerturkey]

NogDog;10909152 wrote:

I've done something like this in the past:

$ratio = (($old_x / $old_y) > ($new_w / $new_h)) ? $new_w / $old_x : $new_h / $old_y;
$thumb_w = (round($ratio * $old_x));
$thumb_h = ($ound($ratio * $old_y));

thank you kindly sir, works perfect. - I was having such troubles grasping the logic.