src/ImboClient/Http/ImageUrl.php
public function contrast($alpha = null, $beta = null) {
        $params = array();

        if ($alpha !== null) {
            $params[] = 'alpha=' . (float) $alpha;
        }

        if ($beta !== null) {
            $params[] = 'beta=' . (float) min(1, max(0, $beta));
        }

        return $this->addTransformation(
            'contrast' . ($params ? ':' . implode(',', $params) : '')
        );
    }
public function contrast($alpha = null, $beta = null) {
        $params = array();

        if ($alpha !== null) {
            $params[] = 'alpha=' . (float) $alpha;
        }

        if ($beta !== null) {
            $params[] = 'beta=' . (float) min(1, max(0, $beta));
        }

        return $this->addTransformation(
            'contrast' . ($params ? ':' . implode(',', $params) : '')
        );
    }
public function contrast ( $ alpha = null , $ beta = null ) { $ params = array ( ) ; if ( $ alpha !== null ) { $ params [ ] = 'alpha=' . ( float ) $ alpha ; } if ( $ beta !== null ) { $ params [ ] = 'beta=' . ( float ) min ( 1 , max ( 0 , $ beta ) ) ; } return $ this -> addTransformation ( 'contrast' . ( $ params ? ':' . implode ( ',' , $ params ) : '' ) ) ; }
Add a contrast transformation

@param float $alpha Adjusts intensity differences between lighter and darker elements
@param float $beta Where the midpoint of the gradient will be. Range: 0 to 1
@return self
Add a contrast transformation