Method for acquiring histogram, method for dynamically adjusting luminance and image processing apparatus

A method for dynamically adjusting luminance of a dynamic video image, which is applied to an image processing apparatus, wherein the method comprises the following steps:

• acquiring luminance data of pixel points of the dynamic video image;
• performing separate statistical processing on frequencies of first luminance data with the minimum luminance value and second luminance data with the maximum luminance value in the luminance data, to draw a first histogram corresponding to the luminance data after the statistical processing;
• acquiring a main distribution range of luminance according to the first histogram;
• and
• level-stretching luminance of the dynamic video image according to the first histogram and the main distribution range to dynamically adjust the luminance of the dynamic video image;
• wherein the step of performing separate statistical processing on frequencies of first luminance data with the minimum luminance value and second luminance data with the maximum luminance value in the luminance data, to draw a first histogram corresponding to the luminance data after the statistical processing comprises:
• expanding a luminance range of the luminance data;
• performing separate statistical processing on the frequencies of the first luminance data and the second luminance data, and performing frequency statistics processing on other luminance data except the first luminance data and the second luminance data according to a preset condition;
• generating a second histogram corresponding to the luminance data after the frequency statistics processing;
• and
• removing first luminance data in a first statistical bar in the second histogram, and removing second luminance data in a last statistical bar, to obtain the first histogram.