[RESOLVED] Need help with logic (math)

[zzz]

OK, I am uploading an image and would like to created a thumbnail. I need to calculate it's size before I send it to the class for resizing.

I have two values

$thumb_height = 100;
$thumb_width = 50;

That's the final result I need.

I also have the values of the original images before it's resized:

$original_height = $valH;
$original_width = $valH;

Here's what needs to happen:

1. I determin which side is bigger (let's say it height)

   if ($original_height > $original_width) {
      // then  need to resize the smaller size to my thumb's size
      // so I do that and get
      $new_width = $thumb_width;
   
   }
   

   
   
   Now I need to:
   1. Calculate the height of the resized image -- it's scaled proportionally.
   2. Subtract from it the desired height
   2. Split the value in two and
   3. Crop from both sides of the image
   
   I can do everything all the way until resizing the thumbnail and need help to calculating the new height after I scale the image.
   
   Writer's block.

[Weedpacket]

You've already written down exactly what you want to do.... scaling the height in the same proportion that the width has been scaled by would be....

$new_height *= $original_width/$new_width

[zzz]

Well, I just realized that it's not that simple.

My target thumbnail has particular size.
By dividing the height by width I'll get a ratio number.

Now I need to divide the source image's height by weight and get its ratio. If the ratio of the source file is less then that of the target I can not scale the width because after scaling the height will be shorter then the target height. So if the ratio is less I need to reverse the process and scale the height first and then crop the extra width.

Me thinks better after food!