Helbling enhances the image quality of affordable camera modules

(CONNECT) A team from the Zurich-based engineering and consulting firm Helbling has developed a practice to improve the image quality of inexpensive cameras. As the experts state in a technical article, investigations were carried out with the aim of achieving the closest possible approximation to the image quality of the cameras of current smartphones. This is now considered the standard, they say - even for industrial companies that work with Helbling on technical development. In the laboratory, various models of so-called low-cost cameras from the industrial and consumer sectors were analysed and tests were carried out. It has been shown that although the iPhone is superior in some areas, it is possible to adapt, particularly in terms of colour reproduction.

The experts assessed the image quality using a camera test stand that can be used to systematically measure standardised norms. The quality features include resolution or modulation transmission and colour reproduction. The Raspberry Pi V2 camera, which costs just under CHF 9, was compared with the iPhone 15 Pro, which is available from around CHF 1,000.

One of the most important results is described as the successful approach of adapting the colour reproduction of the low-cost cameras to that of the iPhone. According to the experts, a defined colour deviation is typical for smartphones, as manufacturers such as Apple and Samsung intensify red or green hues. This makes pictures appear more vivid. The experts were also able to implement this for the inexpensive camera with the help of so-called ISP tuning. This requires not only expertise in tuning, but also knowledge of "where and to what extent the color values need to deviate from the original". This approach is now already being applied in Helbling's day-to-day work on current client projects.

According to the article, the analyses and evaluations have made it clear that the entire system of a camera is relevant for image quality: including optics, image sensor, camera driver and, ultimately, algorithms for image measurement. One of the reasons for the iPhone's better resolution and slightly better imaging performance is software-based sharpening. According to the experts, a filter was able to visibly improve the image sharpness of the low-cost camera in the test, but not across the entire image. ce/yvh