Question

I have dynamic loaded images wich cannot be larger than 115px. I get them from an external source so I have no control over it.

I could get the image sizes with:

$list = getimagesize($imagePath);
$width = $list[0];
$height = $list[1];

But now I need to resize if they are larger than 115px. Tried this but it didn’t keep the proportion:

$height = round(($height * $width) / $width);

Can someone help me with this?
Thanks in advance.

Answer 1

You should consider using imagecopyresampled or imagecopyresized.

If you’re looking to keep the image scaled properly, you’ll have to throw in a bit more arithmetic, but it shouldn’t be too bad.

Here’s a bit of pseudocode for scaling the image:

$max_height = 115;
if ($height > $max_height)
{
    $scale = $max_height / $height;
    $height = intval($height * $scale);
    $width  = intval($width  * $scale);
}

Here’s a more generic form for if height and width must be less than 115:

$max_size = 115;
if (max($height, $width) > $max_size)
{
    $scale = $max_size / max($height, $width);
    $height = intval($height * $scale);
    $width  = intval($width  * $scale);
}

This guarantees that the largest dimension of the image (be it height or width) will be no greater than 115.