Find new proportional dimensions of an image in PHP

Question

I have a site and I want to upload an image and resize it because I have to put it into a div with a certain dimension.

For example my max-width is 200px and max-height is 100px

I want to upload the image and check width and height, if they are bigger than the max-width or max-height I want to find the size of the image to stay inside that div.

How can I resize proportionally the size of the image? I only want to find new width and new height in base of my div 200px*100px

This is my script:

            if(move_uploaded_file($tmp, $path.$actual_image_name))
            {
                list($width, $height, $type, $attr) = getimagesize($tmp);
                if($width>200){
                    //too large I want to resize
                }
                if($height>100){
                    //too height I want to resize
                }
                echo(base_url().$path.$actual_image_name);
            }

Answer 1

You can use the function below to stay inside a bounding box. EG 200x200. Just send in the filelocation and the max width and height. It will return an array where $ar[0] is the new width and $ar[1] is the new height.

Its written out in full so you can understand the math.

<?php
function returnSize($maxW,$maxH,$img) {
    $maxW = ($maxW>0 && is_numeric($maxW)) ? $maxW : 0;
    $maxH = ($maxH>0 && is_numeric($maxH)) ? $maxH : 0;

    // File and new size
    if (!file_exists($img)) {
        $size[0]=0;
        $size[1]=0;
        return $size;
    }

    $size = getimagesize($img);

    if ($maxW>0 && $maxH>0) {
        if ($size[0]>$maxW) {
            $scaleW = $maxW / $size[0];
        } else {
            $scaleW = 1;
        }

        if ($size[1]>$maxH) {
            $scaleH = $maxH / $size[1];
        } else {
            $scaleH = 1;
        }

        if ($scaleW > $scaleH) {
            $fileW = $size[0] * $scaleH;
            $fileH = $size[1] * $scaleH;
        } else {
            $fileW = $size[0] * $scaleW;
            $fileH = $size[1] * $scaleW;
        }

    } else if ($maxW>0) {
        if ($size[0]>$maxW) {
            $scaleW = $maxW / $size[0];
        } else {
            $scaleW = 1;
        }

        $fileW = $size[0] * $scaleW;
        $fileH = $size[1] * $scaleW;

    } else if ($maxH>0) {
        if ($size[1]>$maxH) {
            $scaleH = $maxH / $size[1];
        } else {
            $scaleH = 1;
        }

        $fileW = $size[0] * $scaleH;
        $fileH = $size[1] * $scaleH;

    } else {
        $fileW = $size[0];
        $fileH = $size[1];
    }

    $size[0] = $fileW;
    $size[1] = $fileH;

    return $size;
}
?>