Portable electronic device with auto-exposure control adaptive to environment brightness and image capturing method using the same

摘要

A portable electronic device with camera function and an image capture method with auto exposure control. The disclosed method comprises the following steps: obtaining a pre-view frame from a camera module; dividing the pre-view frame into a plurality of blocks and calculating representative brightness values of the blocks; assigning weight values to the blocks according to the representative brightness values; obtaining a weighted brightness value by performing a weighted operation on the representative brightness values based on the weight values of the blocks; setting an auto exposure parameter of the camera module based on the weighted brightness value; and controlling the camera module for capturing images based on the auto exposure parameter.

主权项

1. A portable electronic device with camera function,comprising:
a camera module; and a processor for executing software, the software comprising:
a pre-view unit, configured to obtain a pre-view frame from the camera module;an auto exposure control unit, comprising:a block brightness calculation module, configured to divide the pre-view frame into a plurality of blocks and calculate representative brightness values of the plurality of blocks, wherein a representative brightness value of a block is represented by an average of luminance values of all pixels of the block;a brightness weight assignment module, configured to assign weight values to the plurality of blocks according to the representative brightness values, the weight values comprising a first weight value, a second weight value and a third weight value, the first weight value being larger than the second weight value, and the second weight value being larger than the third weight value, so as to emphasize the blocks of higher representative brightness values;a weighted brightness calculation module, configured to obtain a weighted brightness value by performing a weighted calculation on the representative brightness values of the blocks according to the weight values of the blocks; andan exposure parameter setting module, configured to set at least one auto exposure parameter of the camera module based on the weighted brightness value; andan image capture unit, configured to control the camera module for capturing images based on the at least one auto exposure parameter, wherein the brightness weight assignment module is configured to:set a plurality of brightness threshold values according to a statistical analysis on the representative brightness values of the blocks, and set a plurality of weight values according to the brightness threshold values;compare the representative brightness values of the plurality of blocks with the brightness threshold values and assign corresponding weight values to the plurality of blocks.