Video Decoder Dependent Quantization Complexity Reduction

The patent divides the quantization process into multiple independent quantizers (first quantizer and second quantizer) that operate in parallel on different coefficient groups. Each quantizer can be independently configured with different quantization steps, allowing complex quantization to be broken down into simpler, manageable segments that reduce overall coding complexity while maintaining or improving coding efficiency.

The patent introduces dynamic selection of quantization modes and steps based on transform coefficient characteristics. The system can adaptively choose between different quantization strategies (e.g., switching between first and second quantizers) depending on the specific video content and coefficient distribution, thereby optimizing coding efficiency without requiring fixed complex coding modes for all scenarios.

The patent segments the transform coefficients into different groups that are processed by separate quantizers. By dividing coefficients into distinct groups (e.g., based on frequency bands or spatial regions), each quantizer can apply optimized quantization steps to its specific group, achieving high quantization precision while keeping each individual quantizer's complexity manageable through independent operation.

The patent applies different quantization steps and strategies to different coefficient groups based on their local characteristics. Important coefficients (e.g., DC coefficients or high-energy AC coefficients) receive finer quantization with smaller steps, while less important coefficients use coarser quantization with larger steps. This local optimization achieves high overall precision without requiring all quantizers to be maximally complex.