Distortion policy of buffer-constrained rate control for real-time VBR coders

Area of Science:

• Digital image processing
• Video compression algorithms
• Rate control techniques

Background:

• Variable bit rate (VBR) coders offer efficient compression but face challenges in buffer management.
• Traditional rate policies prioritize buffer stability, potentially sacrificing constant visual quality.
• Achieving both buffer stability and consistent distortion in VBR coding is a significant challenge.

Purpose of the Study:

• To introduce and analyze a novel distortion policy for buffer-constrained rate control in VBR coders.
• To investigate methods for balancing buffer state stability and minimizing distortion variation.
• To adapt rate control strategies for time-varying image characteristics.

Main Methods:

• Formulation of a distortion policy considering both buffer state and distortion levels.
• Utilization of a weighting factor within the cost function to manage buffer and distortion trade-offs.
• Implementation and evaluation using a JPEG-like image coder.

Main Results:

• The distortion policy effectively manages buffer-constrained rate control.
• Adjustable weighting factors allow for stable buffer states and reduced distortion variation.
• Switching and adaptive methods improve performance for time-varying image content.

Conclusions:

• The proposed distortion policy offers a flexible approach to VBR rate control.
• It successfully addresses the trade-off between buffer stability and distortion consistency.
• This method enhances the efficiency and quality of VBR image and video compression.