1. Interpolation methods for Image Transcoding Asmar Azar Khan 2005-06-0003

2. Transcoding: Scope and Application Multimedia Networks  Different Nodes  Image Resolution  Different Encoding Schemes MPEG-1 to H.261 MPEG-2 to H.263 MPEG-1 to DV

3. Transcoding: Scope and Application Spatial Resolution  CIF (352 x 288)  QCIF (176 x 144)  VGA (640 x 480) Mobile Devices  PDAs  Gaming Consoles

4. Image Scaling Filtering  Aliasing Re-sampling  Continuous Image  Sampling

5. Image Scaling QCIF LP-Filtering VGA M N LP-Filtering

6. Image Scaling QCIF Interpolator VGA Sampler

7. Ideal Interpolation Interpolators  Preserves high frequency  No aliasing Approximators

8. Nearest Neighbor Nearest Pixel Value  Less Complex  Low Quality  Edge handling

9. Linear Interpolation:

10. Bicubic Interpolation

11. Quadratic Interpolation

12. Cubic B-Spline Interpolation

13. Simulations and Performance Metric Fourier Analysis Pass-band Cutoff Points Stop-band Subjective/Visual Quality Interpolation Error  SNR Computational Complexity Runtime Memory Overhead

14. Hardware and Software Encoders in Software Memory and Processing Issues  Real time issues Hardware design  Nearest Neighbor  Bicubic Interpolation Cubic B-Spline Hardware Design  Memory Requirement  Reducing MACs  FPGA Availability

15. References Survey: Interpolation Methods in Medical Image Processing Thomas M. Lehmann Cubic Splines for image Interpolation and Filtering Hseih S. Hou Real-Time FPGA-Based Architecture for Bicubic Interpolation: An Application for Digital Image Scaling Marco Aurelio Nuño-Maganda, Miguel O. Arias-Estrada Cubic Convolution Interpolation for Digital Image Processing Robert g. Keys

16. Questions !