Stereo matching device and method for determining concave block and convex block

• US 8,989,481 B2
• Filed: 02/13/2012
• Issued: 03/24/2015
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Original Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Inventors: Hsu, Hung-Min
• Primary Examiner(s): Chang, Jon
• Assistant Examiner(s): Mistry, Oneal R
• Application Number:
  US13/371,659
• Publication Number:
  US 20130208975A1
• Time in Patent Office: 1,135 Days
• Field of Search: None
• US Class Current: 382/154
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 7/593 from stereo images

Abstract

A stereo matching device used in a stereoscopic display system for determining a concave block and a convex block is provided. The stereo matching device comprises a receiving module for receiving a first and a second view-angle frames, a computation module, a feature extraction module and an estimation module. The computation module generates a disparity map having disparity entries respectively corresponding to blocks of the first view-angle frame. The feature extraction module generates feature maps each having feature entries respectively corresponding to the blocks. The estimation module comprises a reliability computation unit for computing a feature reliability of each of the blocks based on the feature maps and a comparator unit for filtering out unqualified blocks according to at least one reliability threshold to generate a plurality of candidate blocks and further determining the concave block and the convex block.

Claims

1. A stereo matching method used in a stereo matching device of a stereoscopic display system for determining a concave block and a convex block, wherein the stereo matching method comprises:

receiving a first view-angle frame and a second view-angle frame;

dividing the first view-angle frame into a plurality of blocks, wherein each of the blocks comprises a plurality of pixels;

generating a disparity map having a plurality of disparity entries respectively corresponding to the plurality of the blocks according to the first view-angle frame and the second view-angle frame;

performing a feature extraction process on each of the blocks to generate a plurality of feature maps, wherein each of the feature maps has a plurality of feature entries respectively corresponding to the blocks;

computing a feature reliability of each of the blocks based on the plurality of the feature maps, wherein the feature reliability is a sum of the feature entries of the feature maps;

filtering out a plurality of unqualified blocks according to a comparison result between the feature reliability of each of the blocks and at least one reliability threshold to generate a plurality of candidate blocks; and

determining the concave block and the convex block according to a maximum disparity entry and a minimum disparity entry the candidate blocks, wherein the concave block corresponds to the maximum disparity entry of the disparity map and the convex block corresponds to the minimum disparity entry of the disparity map.

2. The stereo matching method of claim 1, wherein the step of performing the feature extraction process further comprises:

generating a color segment map having a plurality of color feature entries; and

generating an edge map having a plurality of edge feature entries.

3. The stereo matching method of claim 2, wherein the step of performing the feature extraction process further comprises:

generating an attention map having a plurality of attention feature entries.

4. The stereo matching method of claim 2, wherein step of computing the feature reliability further comprises:

generating a similarity reliability map according to the color segment map and the disparity map, wherein the disparity similarity reliability map has a plurality of similarity reliability entries each corresponding to a similarity strength of each of the blocks;

generating an edge reliability map according to the edge map, wherein the edge reliability map has a plurality of edge reliability entries each corresponding to an edge strength of each of the blocks;

generating a matching-cost reliability map according to the minimal sum of absolute difference of each of the blocks, wherein the matching-cost reliability map has a plurality of matching-cost reliability entries each corresponding to a matching-cost strength of each of the blocks; and

generating the feature reliability of each of the blocks by summing the plurality of similarity reliability entries, the plurality of edge reliability entries and the plurality of matching-cost reliability entries of each of the blocks.

5. The stereo matching method of claim 4, wherein step of computing the feature reliability further comprises:

generating an attention reliability map according to the attention map, wherein the attention map has a plurality of attention reliability entries each corresponding to an attention strength of each of the blocks, wherein the feature reliability of each of the blocks is generated by summing the plurality of similarity reliability entries, the plurality of edge reliability entries, the plurality of matching-cost reliability entries and the plurality of attention reliability entries of each of the blocks.

6. The stereo matching method of claim 1, wherein the step of generating the disparity map further comprises computing a minimal sum of absolute difference between each of the blocks of the first view-angle frame and each of a plurality of corresponding blocks of the second view-angle frame.

7. The stereo matching method of claim 1, wherein the step of receiving the first view-angle frame and the second view-angle frame further comprises performing a low pass filtering process and a down sampling process on the first view-angle frame and the second view-angle frame respectively.