Depth Map Upsampling Using Adaptive Support Windows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing disparity map estimation algorithms face high computational complexity when processing high-resolution data, making real-time applications challenging, especially for 3D TVs, and bilateral filters can lead to incorrect up-scaling and increased complexity due to changing weight distributions and disconnected support windows.
Innovation Solution
The method employs adaptive support windows determined by vertical and horizontal bounds in high-resolution color images for up-sampling low-resolution depth maps, using nearest neighbor interpolation and summed area tables to reduce computational complexity and ensure connected support regions, thereby achieving precise high-resolution depth maps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If bilateral filters are used for up-sampling depth maps, then up-sampling precision is improved, but computational complexity increases tremendously
Solution Approach 1:
The patent segments the support window into multiple sub-windows based on depth discontinuity detection. By dividing the filtering region into smaller segments where depth is relatively uniform, the computational complexity is reduced while maintaining precision. Each sub-window can be processed independently with simpler operations, avoiding the need to compute bilateral weights across the entire large window.
Solution Approach 2:
The patent performs preliminary detection of depth discontinuities and identifies support regions before executing the up-sampling operation. By pre-segmenting the image based on depth edges and preparing sub-window structures in advance, the actual filtering process becomes computationally lighter. This preliminary analysis allows subsequent filtering to operate on smaller, pre-defined regions rather than computing weights dynamically across large windows.
2Measurement precision
If window size is increased for better up-sampling, then up-sampling quality is improved, but computational complexity increases
Solution Approach 1:
The patent divides large windows into smaller sub-windows based on depth discontinuity boundaries. This segmentation allows the system to effectively utilize large window sizes for capturing sufficient contextual information while reducing the actual computational burden by processing smaller sub-regions independently. The segmentation strategy enables large effective support regions without the quadratic computational cost of processing the entire large window.
Solution Approach 2:
The patent applies different filtering strategies to different local regions based on depth characteristics. In regions with depth discontinuities, smaller sub-windows are used to preserve edges, while in smooth regions, larger effective coverage is achieved through adaptive combination of sub-window results. This local adaptation optimizes the balance between window size benefits and computational cost for each specific region.
3Manufacturing precision
If bilateral filters assume intensity edges involve depth discontinuities, then edge preservation is improved, but incorrect up-scaling occurs in regions with smooth depth variations
Solution Approach 1:
The patent applies different filtering behaviors to different local regions based on actual depth discontinuity detection. In regions where depth discontinuities are detected at intensity edges, the filtering preserves edges similar to bilateral filters. In regions where intensity edges do not correspond to depth discontinuities, the filtering allows smooth variations by adapting the support region boundaries. This local differentiation resolves the contradiction by making the edge preservation behavior context-dependent rather than universal.
Solution Approach 2:
The patent makes the support region boundaries dynamic rather than fixed, allowing them to adapt to local depth characteristics. The support regions are adjusted based on detected depth discontinuities, expanding in smooth regions and contracting at actual depth edges. This dynamic adaptation enables the filter to preserve edges where needed while allowing smooth variations where intensity edges do not correspond to depth boundaries, improving overall up-scaling reliability.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A device and a method of up-sampling low resolution depth data is described, in particular in the form of a range map or a disparity map of stereo content, comprising the following successive steps: up-scaling the low resolution depth data to the desired resolution using a nearest neighbour interpolation to receive an up-scaled disparity map, detecting the horizontal and vertical bounds of each pixel of a high resolution colour image based on intensity differences, wherein the low resolution depth data correspond to the high resolution colour image, combining the up-scaled disparity map and the detected vertical and horizontal bounds by applying an averaging filter among an arbitrary shaped region by the utilization of horizontal and vertical integral data of the up-scaled disparity map to receive a high resolution disparity map.