Emprex KIT-101 PC180 webcam resolution issue

I have an Emprex webcam, which is identified using camorama as a Pixart PAC207-BCA camera with 176x144 resolution even though the camera is capable of 640x480 resolution.

The program cheese is able to display an image at full resolution but saves recorded images at 320x240.

I have gspcav-pae and gspcav-xen installed.