Digital Camera Processor Design And System Integration

The thesis analyzes and researches the design theories and methodologies of digital camera processors, and proposes two system-on-a-chip (SoC) designs.At first, the architecture of digital still camera system is discussed, especially for the theory of image sampling and processing. Then, the research is emphasized on the three main functions of a digital camera processor: architecture design, image processing and image compression. These topics are discussed and realized with new architectures, advanced algorithms and SoC designs. The SoC design methodology is also discussed in the thesis.In the design of processor architecture, a novel DMA-based architecture for digital camera processor is proposed. The architecture has been optimized for digital camera system, and has a trade-off among bus bandwidth, system performance and flexibility. The architecture can achieve efficient application in IP-based digital camera processors.In image processing, the pre-processing and post-processing flows are both discussed. An advanced adaptive auto exposure (AE), auto white balance (AWB) and auto focus (AF) algorithm is proposed. The algorithm can improve searching speed when keeping enough precision. A real-time image processing flow involving color interpolation, white balance, gamma correction, color correction, color space conversion and edge enhancement is also included in the design.In image compression, the IP's of JPEG and JPEG2000 are designed. The algorithm theories, standards and proper architectures are researched. Some design guidelines are also given. The designs are proven by the experimental results.At last, the SoC design methodologies, especially the IP design flow, are discussed. Some important design strategies are also discussed such as design for synthesis, timing optimization, design for test and low power design. Two digital camera processors are designed and tested. One is a JPEG-based CCD digital camera processor and another is a JPEG2000-based digital camera processor. The results show that the chips have achieved the advanced level in the world.