Adaptive Precision Extension for Image Block Encoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional image compression standards like AVC and HEVC face inefficiencies due to the need for increased bit depth in intermediate calculations, leading to complex and costly hardware or software implementations, especially when dealing with varying dynamic ranges in image blocks.
Innovation Solution
The method introduces a local dynamic range for image blocks, allowing adaptive precision extension by calculating new pixel values based on the difference between the maximum and minimum pixel values, which reduces the bit depth required for calculations without losing precision, and encodes this information for efficient encoding and decoding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If increased bit depth is used for intermediate calculations to maintain precision, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The image is divided into multiple blocks, and each block is processed independently with its own local dynamic range calculation. This segmentation allows the system to use lower bit depth for each individual block's intermediate calculations while maintaining overall precision, as each block's calculations are self-contained and do not require the full precision of the entire image.
Solution Approach 2:
Instead of using a uniform high bit depth for all calculations, the patent applies local dynamic range extension only where needed within each block. The precision extension is adapted to the local characteristics of each block (based on its specific min and max pixel values), allowing lower bit depth in regions with smaller dynamic ranges while maintaining precision only where the local dynamic range requires it.
2Measurement precision
If increased bit depth is used for intermediate calculations to maintain precision, then measurement precision is improved, but productivity decreases
Solution Approach 1:
By dividing the image into blocks and processing them independently with local dynamic range calculation, the computational burden is distributed and reduced. Each block requires fewer bits for intermediate calculations compared to processing the entire image with global dynamic range, thereby improving computational efficiency while maintaining precision within each block.
Solution Approach 2:
The patent dynamically adjusts the bit depth parameter for intermediate calculations based on the local dynamic range of each block. Instead of using a fixed high bit depth for all calculations, the system adapts the precision requirement to match the actual dynamic range needed for each block, reducing unnecessary computational overhead and improving processing speed.
3Measurement precision
If uniform high precision is applied to all image blocks, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent implements local dynamic range extension that adapts to the specific characteristics of each image block. The precision extension is applied selectively based on the local min and max pixel values within each block, rather than applying uniform high precision across the entire image. This reduces software complexity by avoiding unnecessary precision operations in blocks that don't require them.
Solution Approach 2:
The system dynamically changes the precision parameter for each block based on its local dynamic range characteristics. By calculating the local min and max values and adapting the bit depth accordingly, the software avoids the complexity of maintaining uniform high precision throughout the entire image, while still ensuring sufficient precision where needed.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A method for encoding and decoding an image block, an encoder, and a decoder are provided. The method for encoding an image block comprises: determining a local dynamic range of the block; adaptively precision-extending pixel values of the block based on the local dynamic range of the block; and encoding the block with an adaptively extended precision. The method for decoding an image block comprises: determining a minimum pixel value of the block and an indicating value for indicating a precision extension factor according to precision extension information; decoding the block according to the indicating value; and de-extending precision of the decoded block based on the minimum pixel value of the block and the precision extension factor. The precision of the intermediate calculations may be improved without increasing an original intermediate bit depth used in intermediate calculations.