Infrared Image Characteristics:
Infrared images are created by “measuring” the heat radiated from objects. Compared to visible light images, they generally have lower resolution, lower contrast, lower signal-to-noise ratio (SNR), a blurry visual effect, and their grayscale distribution is a nonlinear relationship with the reflective characteristics of the target.
Typically, infrared detectors send 16-bit single-channel images, which are converted to 8-bit single-channel images for display. If shown as 24-bit, it implies that R=G=B with each channel at 8-bit.
Why are infrared images sometimes black-and-white and other times color?
Infrared cameras capture grayscale images, similar to a photo in a black and white newspaper. To create color images, grayscale images undergo pseudo color enhancement, where each pixel's grayscale level is transformed into a specific color based on a mapping function, obtaining a color image.
Infrared images are single-channel images, not three-channel images. The color infrared images we see are actually pseudo color images, which are different from the color we see in visible light.