Nowadays, mobile phone set makers are implementing a full screen display by changing the mounting form factor of the front camera, which is superior in design. When it comes to smart phone front-facing cameras, the hole type front-facing camera degrade the industrial design, while pop-up style camera has also limitation in terms of waterproofness and durability. In the case of Under Display Camera(UDC) which is in its final form factor by design, where a camera is placed underneath the screen, the display panel on the light-receiving path degrades the camera optical sensitivity and causes decrease in image quality performance due to regular display panel pattern. In order to commercialize the UDC, improving image quality of the UDC and exact measurement are crucial. However, subjectively evaluating image taken through the display panel is challenging task measure the image quality performance. This paper introduces a numeric based UDC image quantitative measurement method as a more objective evaluation way.