PHP图像比率宽度和高度，顶部和左侧

Posted 2021-02-23

Returns array with information like:
Input image
width 200
height 200

print_r(ratioResize('path/to/image.ext' , 100 , 50));



output:


array(
[ratio] => .5,
[height] => 50,
[width] => 50,
[left] => 25,
[top] => 25
);

function ratioResize( $image , $maxwidth , $maxheight , $forcewidth=false ){
		$return = array();list( $w , $h ) = getimagesize( $image );
		if($w < $maxwidth && $h < $maxheight && !$forcewidth)return array('width'=>$w,'height'=>$h,'left'=>($maxwidth-$w)/2,'top'=>($maxheight-$h)/2,'ratio'=>1);
		$rw = $maxwidth/$w;	$rh = $maxheight/$h; //GET HEIGHT AND WIDTH RATIO 
		$return['ratio'] = $rw <= $rh?$rw:$rh;
		$return['height'] = round($h*($return['ratio']));
		$return['width'] =  round($w*($return['ratio'])); //GET CALCULATED DIMENSIONS FROM RATIO
		$return['left'] = ($maxwidth - $return['width'])/2;
		$return['top'] =  ($maxheight - $return['height'])/2;//GET CALCULATED CENTERING PIXELS
		return $return;
	}