Depth Camera Image Transformation via EDIT Processing Order

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Solution Overview

Problem

The integration of depth camera and color camera data in augmented reality systems is hindered by parallax effects, leading to occlusions and errors when depth information from a separate depth camera is mapped to a color camera coordinate system, requiring inefficient occlusion testing and processing.

Innovation Solution

The Efficient Depth Map Transformation (EDIT) method transforms depth camera images into the color camera coordinate system by determining a processing order based on the physical offset between the cameras, allowing for occlusion handling without explicit pixel presence and distance testing, thereby improving processing speed and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If depth camera and color camera are positioned separately to capture images, then depth information can be obtained for 3D mapping in augmented reality, but parallax effects cause occlusion errors when mapping depth data to color camera coordinate system

Engineering Contradiction:
Improvedepth information accuracyVSAvoidocclusion error rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by determining the processing order of depth pixels before performing the depth-to-color coordinate transformation. The system calculates the relative position between depth and color cameras, then establishes a processing sequence that anticipates occlusion relationships. This pre-determined processing order ensures that when multiple depth pixels map to the same color pixel, the correct occlusion hierarchy is already established, eliminating the need for runtime occlusion testing and preventing occlusion errors.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If traditional raster order processing is used for depth map transformation, then implementation is simple, but occlusion errors occur and processing efficiency is reduced due to required occlusion testing

Engineering Contradiction:
Improveprocessing speedVSAvoidtransformation accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary calculation of the processing order based on camera relative positioning before the actual depth transformation. By pre-determining which depth pixels should be processed first based on their spatial relationship to the color camera, the system eliminates the need for runtime occlusion testing. This preliminary arrangement of processing sequence directly improves both processing speed and transformation accuracy simultaneously.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of using the conventional raster scan order (left-to-right, top-to-bottom) and then testing for occlusions, the patent inverts the approach by first determining the correct processing order that inherently handles occlusions, then processing pixels in that order. This inversion eliminates the harmful occlusion testing step while maintaining correct depth mapping accuracy.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If depth pixels are processed without considering processing order, then implementation is straightforward, but occlusion handling requires explicit pixel presence and distance testing which increases complexity

Engineering Contradiction:
Improveimplementation simplicityVSAvoidprocessing algorithm complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent resolves the complexity issue by performing the occlusion handling logic in advance. The processing order is determined before the actual pixel transformation, based on the relative camera positions. This preliminary step encodes the occlusion resolution strategy into the processing sequence itself, so that during the actual transformation, no additional occlusion testing is needed. The complexity is paid once during order determination, not repeatedly during pixel processing.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

EDIT enables efficient and accurate transformation of depth camera images into the color camera coordinate system, reducing processing time and errors associated with occlusions, enhancing the integration of depth data in augmented reality applications.

Implementation Method 1

Because of the parallax effect, the depth map of the depth camera may have a depth value for two points at two different depths where, from the perspective of the color camera, the closer of the two points occludes the further

Methodology Applied
Scientific EffectParallax: Parallax

Data Source

PatentEP3189495B1Method and apparatus for efficient depth image transformation
Publication Date: 2022.04.20 QUALCOMM INC
  • EP3189495B1 patent drawingFigure 1
  • EP3189495B1 patent drawingFigure 2
  • EP3189495B1 patent drawingFigure 3

AI summary

Disclosed are a system, apparatus, and method for depth camera image re-mapping. A depth camera image from a depth camera may be received and a depth camera's physical position may be determined. The depth camera's physical position may be determined relative to an other physical position, such as the physical position of a color camera. The depth camera image may be transformed according to a processing order associated with the other physical position.