the original thumbsgallery can not crop the thumbnails. I have a upgrade for this. You must change the file "resize.image.class.php"
I have add a function before the "ImageCopyResampled"
		$w_new = $this -> new_width;
		$h_new = $this -> new_height;
		$x=$this -> new_width;
		
		$ratio = $width/$height;
		if ($w_new/$h_new > $ratio) {
			//portrait
		   $this -> new_height = $h_new/$ratio;
		   $x=0;
		} else {
			//landscape
		   $this -> new_width = $h_new*$ratio;
		   $x=$this -> new_width - $x;
		}
		ImageCopyResampled( $image_c, $new_image, 0, 0, $x, 0, $this -> new_width, $this -> new_height, $width, $height );
The ´portraits cropped bottom and the landscape images cropped right and left.
When you dont crop right and left the landscape images, then leave the original row:
		ImageCopyResampled( $image_c, $new_image, 0, 0, 0, 0, $this -> new_width, $this -> new_height, $width, $height );