Picture Decoding Apparatus Inverse Quantization Lookup Table
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Solution Overview
Problem
Conventional picture coding and decoding methods require significant computational loads for quantization and inverse quantization processes, particularly due to the need for numerous multiplications and divisions in processing frequency coefficients.
Innovation Solution
A picture coding and decoding method that performs inverse quantization and inverse orthogonal transformation on a block-by-block basis, reducing the number of multiplications required by pre-computing quantization steps and storing the results for efficient retrieval during the decoding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional picture coding and decoding methods are used, then accurate inverse quantization and inverse orthogonal transformation can be performed, but significant computational loads are required due to numerous multiplications and divisions
Solution Approach 1:
The patent pre-calculates and stores quantization step information and orthogonal transformation coefficients in lookup tables before decoding. During actual decoding, the system retrieves pre-computed values from these tables rather than performing calculations in real-time, significantly reducing the computational load of multiplications and divisions while maintaining decoding accuracy
Solution Approach 2:
The patent creates simplified copies of the complex mathematical operations by storing pre-computed transformation coefficients and quantization steps. Instead of performing full multiplication and division operations, the system uses retrieved values from lookup tables that represent these operations, reducing computational complexity while preserving the essential decoding function
2Productivity
If pre-computation of quantization steps is performed, then the number of multiplications in inverse orthogonal transformation is reduced, but additional memory storage is required for pre-computed values
Solution Approach 1:
The patent performs quantization step calculations and orthogonal transformation coefficient computations in advance, storing the results in lookup tables. This pre-computation approach trades memory storage for reduced real-time computational load, improving processing efficiency during actual decoding operations
Solution Approach 2:
The patent transforms the computational problem from the time domain (performing calculations during decoding) to the space domain (storing pre-computed values in memory). By moving the computational burden to a different dimension (memory storage), the system achieves faster real-time processing at the cost of additional storage requirements
Data Source
AI summary
The picture decoding method according to the present invention is a decoding method for decoding coded pictures by inverse quantization and inverse orthogonal transformation, in which a quantization matrix which defines a scaling ratio of a quantization step for each component is multiplied by a multiplier, which is a coefficient for frequency transformation or a quantization step, and also, a result of the multiplication is multiplied by a quantized value, as a process of inverse quantization.