A blue rectangle of 100 × 360 pixels is programmed to show on the display of the smart phone so that the user can conveniently adjust the position and orientation of the smart phone in such a way that the glass bottle is properly fitted in. In addition, there are three regions of interest (ROIs) assigned on the display of the smart phone. The first two ROIs function as reference ROIs. Each of them contains 60 × 60 pixels and is positioned on the side of the blue rectangle. These two reference ROIs are used to collect the image data in red, green, and blue color planes associated with the white reference scene. Another 60 × 60 pixel ROI is specifically assigned between the two ROIs and it is inside the blue rectangular area. Similarly, its purpose is to collect the image data in red, green, and blue color planes for the solution under investigation.