The study of a camera sensor behavior and performance must be done considering different dimensions:
- In the photo image surface dimension —the spatial dimension— represented by the X-Y plane in the following picture.
- In the temporal dimension represented by the T axis in the following picture.
Very often the analysis is done in the image surface dimension, studying the color values of pixels on the same image. However, another way to analyze a sensor performance is considering the temporal dimension. This refers to the study of the pixel color values of the same —or equivalent— pixels on different photos of the same scene taken under the same conditions.
The analysis using these different dimensions is required because the physical elements, determining the raw pixel color values in a photo image, are random variables when they are analyzed from the perspective of one dimension and they can be non-random variables when analyzed from another dimension.
For example, to characterize the sensor response under specific conditions.