I have a script which uses the following code to resize images to a width of 350pixels, and keeps the height in proportion:

PHP Code:

list($width,$height)=getimagesize($uploadedfile);

$newwidth=350;
$newheight=($height/$width)*$newwidth; 


But also I need it to have a maximum height, say 300 pixels? But I cant really figure out the mathematical formula for it!

Im thinking something along the lines of:

PHP Code:

list($width,$height)=getimagesize($uploadedfile);

if(height>300)
{
newwidth=($width/$height)*300;
}

else
{
$newwidth=350;
$newheight=($height/$width)*$newwidth;
} 


All the ones I have played with use the larger dimesion (whether it be w or H) and resize the other on a % basis. That is the olny way to get an undistorted image.

PHP Code:

$newheight=($height/$width)*$newwidth; 


is still a correct calculation to use though, it brings up the same results.

I am sugest to you keep width and height in same dimension. Otherwise you will get disproportional resizing for higher images.

PHP Code:

$maxWidth_Height = 350;
$sizes = getimagesize($uploadedfile); 

// resize if is width bigger or same like height
if ($sizes[0] >= $sizes[1] && $sizes[0] > $maxWidth_Height) {
    $resize = $sizes[0]/$maxWidth_Height;
    $width = round($sizes[0]/$resize); 
    $height = round($sizes[1]/$resize); 

// resize if is height bigger then width
} elseif($sizes[0] < $sizes[1] && $sizes[1] > $maxWidth_Height) {
    $resize = $sizes[1]/$maxWidth_Height;              
    $height = round($sizes[1]/$resize); 
    $width = round($sizes[0]/$resize);

// don't resize if both dimension are smaller then $maxWidth_Height
} else {
    $width = $sizes[0];
    $height = $sizes[1]; 
} 


I am using this script long time like part of my image gallery without any error.

Shivaji