US 11,736,816 B2
Image sensor circuitry for reducing effects of laser speckles
Mattias Johannesson, Linköping (SE); Johan Melander, Linköping (SE); and Romain Müller, Stegen (DE)
Assigned to SICK IVP AB, Linköping (SE)
Filed by SICK IVP AB, Linköping (SE)
Filed on Feb. 5, 2021, as Appl. No. 17/169,104.
Claims priority of application No. 20158365 (EP), filed on Feb. 19, 2020.
Prior Publication US 2021/0258452 A1, Aug. 19, 2021
Int. Cl. H04N 13/254 (2018.01); H04N 23/81 (2023.01)
CPC H04N 23/81 (2023.01) [H04N 13/254 (2018.05)] 9 Claims
OG exemplary drawing
 
1. A method, performed by an image sensor circuitry comprising an image sensor, for reduction of laser speckle effects in a digital image resulting from the image sensor sensing laser light reflected from an object as part of laser triangulation performed by a 3D imaging system, wherein the method comprises:
per each pixel position (x, y) of at least a subregion of the image sensor:
assigning to said pixel position (x,y) a pixel window (w) comprising said pixel position (x,y) and one or more of its closest neighboring pixel positions,
obtaining first pixel values for each pixel located within said pixel window (w), said first pixel values resulting from the same exposure and corresponding to sensed light from this exposure, and
combining the obtained first pixel values into a single, second pixel value according to a combination function;
wherein the first pixel values and the second pixel values of said pixel positions of said at least subregion of the image sensor are analogue pixel values and said pixel windows (w) assigned to said pixel positions of said at least subregion of the image sensor are one dimensional and oriented in the same direction; and
providing the digital image based on the second pixel values, whereby there is reduction of laser speckle effects in the digital image compared to if the digital image would be based on the first pixel values;
wherein the combining of the first pixel values (v1) into the second pixel value (v2) is made in parallel for pixel positions with non-overlapping pixel windows (w) and sequentially for pixel positions with overlapping pixel windows (w).