Method for automatic exposure regulation and control system

Abstract

The invention discloses an automatic exposure adjustment method and a control system, comprising the following steps: first, setting the initial exposure parameters and determining the scope of the target brightness; secondly, judging whether the average brightness value of the image in the initial state is within the target brightness scope, and if so, do not change the exposure time and the gain value; the invention is characterized in that if the average brightness value of the image in the initial state is not within the target brightness scope, the exposure time is divided into n-levels,gained in each level and gradually adjusted based on a certain step length; the exposure time jumps from one level to another level on the equal-brightness curves so as to achieve the optimal exposure effect through the method of gradually adjusting the gain and the exposure time. The control system comprises a sensor (101), an interface module (102), an automatic exposure control module (103) and a brightness characteristic value calculation module (104); the method and the system are simple and flexible to realize so as to reduce the chip cost; and the adjustment on the equal-brightness curves enables the entire automatic exposure process to be very smooth, without the brightness-darkness staggered flashing situations.

Description

technical field [0001] The invention relates to a method and control system for automatic exposure adjustment, in particular to a method and control system for automatic exposure adjustment applied to film or digital photosensitive components (CCD, CMOS, etc.). Background technique [0002] Exposure is the process of film or digital photosensitive components (CCD, CMOS, etc.) accepting light from the lens to form an image, and the exposure time is the time when the photosensitive component receives light. Under the premise of the same environment and other conditions unchanged, the length of the exposure time is directly proportional to the brightness of the image, that is, the longer the exposure time, the brighter the image, otherwise the darker the image. Obviously, a very important factor affecting exposure is the light source, and there are different light sources in our environment, so the setting of exposure time will also be different. [0003] In daily life, the li...

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Problems solved by technology

[0006] In the invention patent application CN1719328A published on January 11, 2006, an automatic exposure adjustment method and control system are also proposed. It first judges whether the target brightness can be achieved through the gain, and then calculates the required target through the formula if it cannot be achieved. Gain, the optimal exposure time is calculated by the gain, and the time is taken as an integer multiple according to the period of the indoor light source, and the obtained time is then reversed to the gain. Although this adjustment method does not cause jumps during adjustment, it needs to calculate the logarithm. The amount of calculation is relatively large. Although the logarithm can be simplified by using methods such as table lookup, there is a contradiction between storage space and accuracy.

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