Method of anti-blooming in measurement of low-light-level television
Jiali Zhu, Xiaodong Liu, Ping Zhang, Fang Hao, Shiming Zhang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013
Blooming is a normal phenomenon in the measurement of low light level television (LLL TV) due to its inner auto-gain control, which will influence the test result and should be controlled in the measurement process. Analyzing the blooming principle, a solving method was improved by increasing the ambient illumination on the sense of LLL TV, which will decrease the auto-gain value of LLL TV. What’s more, this method was validated in an experiment of resolution measurement of LLL TV by the applying an auxiliary lighting equipment. The auxiliary light equipment was composed with three ground glasses, twelve LED lamps, and a box brushed with diffuse materials inside. The color temperature of LED lamps was 3000K whose value is close to the light source (2856K) of resolution measurement. During the experiment, auxiliary light equipment was placed in front of the LLL TV. By analyzing the output image of the LLL TV, the blooming phenomenon disappeared and the covered resolution image appeared. The result means that the method of increasing the ambient illumination on the sense of LLL TV is an effective way to depress the blooming in measurement of LLL TV, and it can be used to other parameter measurement of LLL TV.