視訊 通訊 homework 1

1. 視訊通訊homework 1 林葦 M023010042

2. Processing Read RGB color space file Transform to YCbCr color space Do DCT and Quantization on Y plane for each 8 ×8 blocks Remove high frequency coefficients (10%, 20%,…) or DC Do Inverse Quantization and Inverse DCT on Y plane Transform to RGB color space Write file (raw RGB file) and calculate PSNR

3. Quantization Q=30

4. Quantization • PSNR=26.6

5. Remove high frequency coefficients x y x=0~7 y=0~7 z=x+y

6. Remove high frequency coefficients ex: If(z>7) DCT[x][y]=0;

7. Remove high frequency coefficients

8. Remove high frequency coefficients 56.3% , PSNR=32.9

9. Remove high frequency coefficients 98.4% , PSNR=21.9

10. Remove high frequency coefficients 56.3% , PSNR=37.9

11. Remove high frequency coefficients 98.4% , PSNR=24.5

12. curve PSNR Dropping rate