Pytlarz
Introduction
Over the past year, the use of video conferences has skyrocketed and with it has come the prevalence of virtual backgrounds. The video conference systems implement body/head detection, attempting to replace the background of the user. This study will explore the believability of these virtual backgrounds, targeting specifically color temperature differences between the user and the background. A relationship will be shown between the color temperature of the original image, the color temperature of the background, and the detectability of the virtual background.
Background
The experiment will be conducted on a 2020 13" Macbook Pro. To ensure accurate processing and color transformation, measurements were taken of the target display and are show below. These measurements were taken in a dark lab using a PhotoResearch PR-740 spectroradiometer.
Red, green, blue and white patches were displayed full screen through the preview app. Since these images are not tagged as DCI-P3 or Rec2020, it is not surprising that we see the display attempting a Rec709/sRGB recreation. Notice the green stimulus produces power in what appears to be the red primary. However, this is the mode that the experiment will be conducted in, so we can use these results as our "native" assumed display.
The chromaticity diagram shows us the color gamut. The primaries are quite close to Rec709/sRGB shown in white. The white point however is far away from the typical D65 (0.3127, 0.3290). We will assume that the images have been rendered properly on the display and will decode accordingly.
The gamma/power response is nearly spot-on a power of 2.1. The peak luminance is 256.5cd/m^2 and the minimum luminance is 0.28cd/m^2 (with the backlight full on).
Methods
Results
Conclusions
Appendix
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