Three images blending engine supporting multicolor formats, various color depths with small-gate size and high-quality image for SOC design

A small color space conversion (CSC) block in video input/ output (VIO) architecture can efficiently support both standards: ITU-R BT.601 and ITU-R BT.709 for RGB and YCbCr color format. The design of an arbitrary (programmable) coefficient helps to reduce the size of CSC block. A new dithering technique is implemented to achieve the advantages, high-quality image and no buffer memory, of error-diffusion algorithm and ordered algorithm. With a small gate count, VIO can also support effectively 4 different inputs with multicolor format, various color depth. This VIO has been used in a SOC chip for mobile phone. The detail of VIO design is described in this paper.