Image processing device of vision sensor
An image processing device is provided. The image processing device includes: a memory; a vision sensor; and at least one processor operatively connected to the memory and the vision sensor, wherein the at least one processor is configured to: receive an event signal from a pixel array of the vision sensor, accumulate the event signal during a preset time and store, in the memory, the event signal as accumulated event data; perform a pixel correction on the stored accumulated event data; and compare the corrected accumulated event data with the event signal to extract valid event data.
1 . An image processing device comprising:
a memory;
a vision sensor; and
at least one processor operatively connected to the memory and the vision sensor,
wherein the at least one processor is configured to:
receive an event signal from a pixel array of the vision sensor;
accumulate the event signal during a preset time and store, in the memory, the event signal as accumulated event data;
perform a pixel correction on the stored accumulated event data; and
compare the corrected accumulated event data with the event signal to extract valid event data.
2 . The image processing device of claim 1 , wherein the preset time is equal to or longer than a cycle based on a flicker frequency of a light source.
3 . The image processing device of claim 1 , wherein the pixel correction corresponds to an operation of scanning the accumulated event data with a window to perform a smoothing filtering, and
wherein the smoothing filtering is configured to generate a corrected pixel value based on a pixel value of a peripheral pixel adjacent to an error pixel having an error pixel value in the window, and replace the pixel value of the error pixel in the accumulated event data with the corrected pixel value.
4 . The image processing device of claim 3 , wherein edges are detected in the corrected accumulated event data after the pixel correction is performed.
5 . The image processing device of claim 1 , wherein the memory is configured to receive, accumulate, and store the event signal that occurs during the preset time.
6 . The image processing device of claim 1 , wherein the at least one processor is configured to:
identify a first signal that overlaps the event signal as a flicker, and
identify a second signal that does not overlap the event signal as a valid event, and generate the second signal as the valid event data, in the corrected accumulated event data.
7 . An image processing device comprising:
a pixel array including a plurality of pixels in a vision sensor, each pixel generating an event signal from light reflected from an object;
a memory operatively connected to the pixel array, the memory being configured to accumulate the event signal during a preset time and to store accumulated event signals as accumulated event data; and
a filter configured to perform a pixel correction on the accumulated event data,
wherein the image processing device is configured to extract, as valid event data, a signal which is non-overlapped with the corrected accumulated event data, the signal being among event signals generated from the pixel array.
8 . The image processing device of claim 7 , wherein the pixel correction corresponds to an operation of scanning the accumulated event data with a window smaller than the pixel array to perform a smoothing filtering.
9 . The image processing device of claim 8 , wherein the smoothing filtering corresponds to an operation of generating a corrected pixel value on a basis of a pixel value of a peripheral pixel adjacent to an error pixel having an error pixel value in the window, and replacing the pixel value of the error pixel in the accumulated event data with the corrected pixel value.
10 . The image processing device of claim 7 , wherein the preset time is equal to or longer than a cycle based on a flicker frequency of a light source.
11 . The image processing device of claim 7 , further comprising an edge detector configured to detect an edge of the object in the corrected accumulated event data and to output edge information.
12 . The image processing device of claim 7 , wherein the memory is a 1-bit memory array configured to store an event status indicating whether an event occurs for each of the plurality of pixels in the pixel array based on the event signal.
13 . The image processing device of claim 7 , wherein the memory is a 2-bit memory array configured to include:
a first memory configured to store an event status in each of the plurality of pixels in the pixel array, and
a second memory configured to store a flicker status in each of the plurality of pixels, based on the event signal.