Gray value and thermal imaging understanding

Introduction to 1.raw

In my previous articles, I also mentioned that I was trying to open a few pictures in raw format. In fact, raw is the data of the original picture. Using the raw picture data for processing and analysis will be better for our image processing.effect, and the fitting speed of the final extracted features will be faster.

The JPEG photos I usually see (about 8M each) come from the photos obtained after image post-processing and compression of Raw format pictures, which will lose a lot of importantInformation.This is why using RAW format images to grade PS is much better than using JPEG images that have been compressed.However, it is still necessary to do it according to the needs at hand. If other formats (jpg, png, etc.) can directly solve the problem, it is also possible.

2.Grayscale value

The grayscale value can actually be understood as the degree of brightness and darkness of the displayed image. Pictures with different digits can display different brightness and darkness levels. For example, if your image is 8bit, then the white and black are divided into logarithmic relationship.Several levels, called "gray levels".The range is generally from 0 to 255, white is 255, black is 0, and corresponding to 16bit, there are 65536 kinds.

Usually, the RGB color level principle we are familiar with is equivalent to the gray value, and the relationship between the two is that the gray value is equal to the RGB composition of the same proportion.

, we all know that the RGB three colors can form any color we have seen so far, and when the RGB three color ratios are the same, they correspond to the grayscale values.

3.The relationship between thermal imaging and gray value

The colorful thermal imaging is often seen in daily life. In fact, thermal imaging has nothing to do with the familiar RGB three colors. As mentioned in 2, whether it is gray value or RGB three colors,Both light and dark can be distinguished according to the level, and this light and dark is the relationship between the image and temperature we want.I also understood it recently after studying, including discussing with my seniors.

Different colors can be customized according to needs, so we can see red/white/black/multi-color thermal images in life. In fact, this is based on personal preference and perception, mainly between light and dark and temperaturerelationship, which also has a specific function.

References:

[1] Gong Jiamin, Wang Beibei, Guo Tao, Liu Huabo, Liu Kunpeng, Xu Jiachi, Zhang Zhengjun. Infrared detection equipment for analyzing the correlation between grayscale and temperature [J]. Infrared Technology, 2016, 38(02):168-174.

[2] Sha Jian. Research on early flame detection based on infrared thermal imaging [D]. Anhui University, 2017.