fast_thresholdfast_thresholdFastThresholdFastThresholdFastThresholdfast_threshold selects the pixels from the input image
whose gray values g fulfill the following condition:
To reduce the processing time, the selection is done in two steps: At first,
all points lying on selected horizontal lines that are specified by their
distance MinSizeMinSizeMinSizeMinSizeminSizemin_size are processed. In the next step the neighborhood
(size (2*MinSize+1) x
(2*MinSize+1)) of all previously selected points are
processed.
注意
On multi-core computers supporting the SSE2 instruction set, thresholdthresholdThresholdThresholdThresholdthreshold
is most likely faster than fast_thresholdfast_thresholdFastThresholdFastThresholdFastThresholdfast_threshold.
fast_thresholdfast_thresholdFastThresholdFastThresholdFastThresholdfast_threshold may only be preferred to thresholdthresholdThresholdThresholdThresholdthreshold if those
features are not available, e.g., on embedded platforms.
fast_thresholdfast_thresholdFastThresholdFastThresholdFastThresholdfast_threshold 在所有参数正确时返回 2 ( H_MSG_TRUE )。
The behavior with respect to the input images and output regions
can be determined by setting the values of the flags
'no_object_result'"no_object_result""no_object_result""no_object_result""no_object_result""no_object_result", 'empty_region_result'"empty_region_result""empty_region_result""empty_region_result""empty_region_result""empty_region_result", and
'store_empty_region'"store_empty_region""store_empty_region""store_empty_region""store_empty_region""store_empty_region" with set_systemset_systemSetSystemSetSystemSetSystemset_system。如有必要，则抛出异常。