空洞修复文献[1] 邻域直方图

1. [1]2012_Depth Hole Filling Using the Depth Distribution of Neighboring Regions of Depth Holes in the Kinect Sensor

1.1. Kinect sensor

1.2. using RGBD images

1.3. Sin titulo

1.3.1. A. Detection of Depth Holes

1.3.1.1. make a binary map of depth holes by detecting zero values in the acquired depth map

1.3.1.1.1. Sin titulo

1.3.2. B. Region Labeling using 8-connectivity

1.3.2.1. depth holes are clustered according to the distances from cluster centers

1.3.2.1.1. need to be grouped

1.3.3. C. Valid Region Generation

1.3.3.1. validation region size

1.3.3.1.1. too narrow, it can be sensitive to noise

1.3.3.1.2. too wide, it can include unnecessary depth information

1.3.3.2. Sin titulo

1.3.3.2.1. Sin titulo

1.3.4. D. Depth Hole Filling

1.3.4.1. Around a depth hole caused by occlusion, depth values between occluding object and occluded object are correlated

1.3.4.2. hole caused by a non-reflective object appears in the form of an isolated hole within the object

1.3.4.2.1. around the depth hole, there are depth values that are correlated

1.3.4.3. corresponds to a dominant peak that is the most distant depth value among multiple peaks

1.3.4.3.1. That’s because the hole mainly occurs at rear objects.

1.3.4.4. compute the histogram of valid regions of each labeled region

1.3.4.4.1. region label l

1.3.4.4.2. dk denotes k-th quantized depth level

1.3.4.4.3. n is the number of pixels of dk in validation region of l-th region

1.3.4.5. fill depth holes

1.3.4.5.1. threshold

1.3.4.6. Sin titulo

1.3.4.6.1. dotted lines denote dominant peaks

1.3.4.7. block-wise process

1.3.4.7.1. uniform depth value on invalid region may cause unnatural artifact

1.3.5. E. Depth Map Refinement

1.3.5.1. depth- color cross-bilateral filter

1.3.5.1.1. remove the artifact

1.3.5.1.2. refine the initial depth map

1.3.5.1.3. Di is an initial depth map with filled depth holes

1.3.5.1.4. Df is a refined final depth map of Di.

1.3.5.1.5. Sin titulo

1.3.6. RESULTS

1.3.6.1. Sin titulo

1.3.6.2. Sin titulo

1.3.6.3. Sin titulo

1.3.7. depth distribution of neighboring regions

1.3.7.1. Unimodal histograms

1.3.7.2. Bimodal histograms

1.3.7.3. Multimodal histograms

1.3.7.3.1. if with a large number of pixels