Spherical Media Rotation Angle Optimization for ERP Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
360-degree cameras and omni-directional cameras output Equi-Rectangular Projection (ERP) format media with significant redundant data, leading to distortion and increased complexity in processing, which affects viewing experience and computational resources due to varying distortion levels across regions in the image or video.
Innovation Solution
A method and apparatus that determine an optimal rotation angle by rotating spherical multimedia content to various angles, performing edge analysis, and selecting the angle with the maximum number of edges aligned to the vertical and horizontal axes to reduce distortion and redundancy, thereby optimizing compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ERP format media is used for 360-degree content, then the media can be output in a standardized projection format, but the media contains significant redundant data and distortion that reduces compression efficiency
Solution Approach 1:
The patent changes the projection parameter by converting from ERP (equirectangular projection) to an optimized projection format that reduces redundancy. This parameter change in the projection method eliminates distorted regions and redundant data, thereby improving compression efficiency while maintaining standardized output
Solution Approach 2:
The patent applies different processing to different regions of the spherical media. By identifying and removing redundant portions (such as overlapping pole regions in ERP), it optimizes the quality of essential regions while eliminating waste, improving overall compression efficiency
2Ease of operation
If ERP format media is processed by media codec, then video compression can be performed by dividing into blocks, but the significant redundant data requires format conversion to another projection format
Solution Approach 1:
The patent performs preliminary optimization of the projection format before compression. By pre-converting ERP to an optimized projection format that eliminates redundancy, it simplifies the subsequent compression process and reduces the complexity of format conversions needed during encoding
3Productivity
If spherical multimedia content is compressed without rotation optimization, then compression can be performed directly on ERP format, but distortion varies across regions affecting viewing experience
Solution Approach 1:
The patent optimizes the rotation angle parameter of the spherical content before compression. By calculating and applying an optimal rotation angle that aligns content features with the projection grid, it achieves uniform distortion distribution across regions while maintaining compression efficiency
Data Source
Figure 1A~1C
Figure 1D~2B
Figure 3A~3B
AI summary
Provided are a method and an apparatus for determining an optimal rotation angle during compression of a spherical multimedia content where the processor may receive first multimedia content corresponding to the spherical multimedia content, generate a plurality of second multimedia contents based on the first multimedia content by rotating the first multimedia content to a plurality of rotation angles, perform an edge analysis on each of the plurality of the second multimedia contents, identify the number of edges aligned to one of a vertical axis or a horizontal axis based on the edge analysis, select second multimedia content with the maximum number of edges, and determine an optimal rotation angle.