Tile Boundary Distortion Reduction via Cross-Tile Wavelet Transform
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Solution Overview
Problem
Conventional remote desktop compression techniques suffer from tile boundary distortion due to edge-of-tile artifacts, limiting compression efficiency and impacting user experience.
Innovation Solution
The method involves processing tile coefficients to produce high and low frequency results, introducing an additional low frequency coefficient at tile boundaries by extrapolating from the last two coefficients of an adjacent tile, and applying discrete wavelet transforms to reduce distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If each tile is individually compressed and decompressed using conventional tiling approach, then compression can be achieved, but edge-of-tile artifacts occur at tile boundaries causing distortion
Solution Approach 1:
The patent merges adjacent tiles by combining their coefficient data and performing a cross-tile transform operation. This allows the transform to span tile boundaries, eliminating the artificial discontinuities that cause edge artifacts while maintaining compression efficiency through unified processing of boundary regions.
Solution Approach 2:
The patent performs preliminary padding of tile coefficients before the transform operation. By extending the coefficient arrays with zero values at the boundaries before transformation, the method prepares the data structure to handle boundary conditions smoothly, preventing artifact formation during the compressive transform process.
2Quantity of substance
If conventional tiling compression is used, then data transmission size is reduced, but tile boundary distortion limits further compression
Solution Approach 1:
The patent merges adjacent tiles by combining their coefficient data and performing a cross-tile transform operation. This allows the transform to span tile boundaries, eliminating the artificial discontinuities that cause edge artifacts while maintaining compression efficiency through unified processing of boundary regions.
3Productivity
If individual tile compression is applied, then processing can be done in parallel, but boundary artifacts reduce overall image quality
Solution Approach 1:
The patent segments the image into tiles for parallel processing but applies a special cross-tile transform operation at the boundaries. This allows most of the image to be processed independently and in parallel, while only the boundary regions require coordinated processing, thus maintaining high productivity while improving boundary quality.
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
This approach significantly reduces tile boundary distortion, enhancing bitmap image quality and allowing for improved compression ratios by ensuring only low-frequency coefficients are present at tile edges, thus improving the transmitted image quality.
Implementation Method 1
processing the coefficients to produce a high frequency result set and a low frequency result set, and introducing an additional low frequency tile coefficient to a boundary between two adjacent tiles by extrapolating a low frequency coefficient
Data Source
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AI summary
A method for removing boundary distortion includes receiving a one-dimensional input signal and determining whether the one-dimensional input signal includes an even number of data elements. If the one-dimensional input signal includes an even number of data elements, an extrapolation operation is performed on one of a first or second boundary of the one-dimensional input signal. The extrapolation operation produces one additional data element. The method may further include performing a mirroring operation on the signal data resulting from the extrapolation operation to produce a mirrored signal, and performing a transform operation the mirrored signal.