16.5 Calibration and Special Testing
541
The images were obtained at different distance to target board, artificial judging
image color, image resolution, and image compression quality.
5) Principle and method of automatic exposure test
The automatic exposure test of morphology camera was the same of descent camera.
The imaging target board was placed at the best distance, and different brightness
was realized by using the light source.
6) Principle and method of image compression test
The image compression test of morphology camera was the same of descent camera.
Target board placed was the best distance. The images were obtained under the
same light brightness to evaluate the images before and after the compression. The
subjective evaluation content was the color authenticity and image sharpness; the
objective evaluation could use the peak signal-to-noise ratio.
7) Principle and method of lunar dust occlusion test
The dust occlusion test was to analyze the camera image quality in different occlusion
of lunar dust.
Method of lunar dust occlusion test is shown in Fig. 16.4. The plain glass which
was covered with lunar dust was close to the camera lens, with different amount
of covered dust for different test. The target board was placed in the best distance,
under the same light brightness, respectively to obtain the separately imaging and
continuously imaging, analyze and evaluate the images by experts.
8) Principle and method of color calibration
The purpose of color calibration was to make the color output of the camera close to
the color perception of the human eye, and the color calibration generally included
two processes: color correction and white balance.
The method of color calibration test is shown in Fig. 16.5.
In color calibration, 24 color standard board and D65 standard light source were
used generally.
In the white balance calibration, the neutral color (black, white, grey) diffuse
standard plate and D65 standard light source were used generally.
Camera to be tested
Image acquisition
equipment
Temperature monitoring
equipment
Target board
Plain glass
Fig. 16.4 Principle diagram of lunar dust occlusion test
541
The images were obtained at different distance to target board, artificial judging
image color, image resolution, and image compression quality.
5) Principle and method of automatic exposure test
The automatic exposure test of morphology camera was the same of descent camera.
The imaging target board was placed at the best distance, and different brightness
was realized by using the light source.
6) Principle and method of image compression test
The image compression test of morphology camera was the same of descent camera.
Target board placed was the best distance. The images were obtained under the
same light brightness to evaluate the images before and after the compression. The
subjective evaluation content was the color authenticity and image sharpness; the
objective evaluation could use the peak signal-to-noise ratio.
7) Principle and method of lunar dust occlusion test
The dust occlusion test was to analyze the camera image quality in different occlusion
of lunar dust.
Method of lunar dust occlusion test is shown in Fig. 16.4. The plain glass which
was covered with lunar dust was close to the camera lens, with different amount
of covered dust for different test. The target board was placed in the best distance,
under the same light brightness, respectively to obtain the separately imaging and
continuously imaging, analyze and evaluate the images by experts.
8) Principle and method of color calibration
The purpose of color calibration was to make the color output of the camera close to
the color perception of the human eye, and the color calibration generally included
two processes: color correction and white balance.
The method of color calibration test is shown in Fig. 16.5.
In color calibration, 24 color standard board and D65 standard light source were
used generally.
In the white balance calibration, the neutral color (black, white, grey) diffuse
standard plate and D65 standard light source were used generally.
Camera to be tested
Image acquisition
equipment
Temperature monitoring
equipment
Target board
Plain glass
Fig. 16.4 Principle diagram of lunar dust occlusion test