1 / 22

DSP C5000

DSP C5000. Chapter 18 Image Compression and Hardware Extensions. Image Compression. Discrete Cosine Transform (DCT) based compression Still image: JPEG. Remove spatial redundancy Video: H263, MPEG4. Remove spatial redundancy Remove temporal redundancy. JPEG Encoder.

juliobell
Download Presentation

DSP C5000

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DSP C5000 Chapter 18 Image Compression and Hardware Extensions

  2. Image Compression • Discrete Cosine Transform (DCT) based compression • Still image: JPEG. • Remove spatial redundancy • Video: H263, MPEG4. • Remove spatial redundancy • Remove temporal redundancy

  3. JPEG Encoder • Image is split into 8x8 pixel block that are processed . • DCT is applied on input block to obtain the frequency data. • Values are read from low to high frequency thanks to zig-zag addressing. • Data are then quantized according to a quality factor. • This output is then run length and entropy coded.

  4. JPEG Decoder • Data are entropy decoded. • They are dequantized according to a quality factor. • Zig-zag addressing to re-order the data pixel by pixel. • Inverse DCT to recover spatial data.

  5. H263 and MPEG4 encoder • Same basic building blocks Hardware accelerator provided by C5509/10

  6. H263 and MPEG4 Decoder • Same basic building blocks Hardware accelerator provided by C5509/10

  7. Hardware Extensions • ‘C5509 and ‘C5510 provide H/W extensions for video compression: • DCT, IDCT • Pixel interpolation • Motion estimation • Hardware extensions are embedded co-processors: • Access to ACx, DARAM and SARAM. • Provide video codec with less than half of the processing bandwidth.

  8. DCT H/W Extension 1 of 5 • Allows 4x4 and 8x8 pixels DCT/IDCT computation: • 2D DCT • 2D IDCT

  9. DCT H/W Extension 2 of 5 • Basic steps to complete a 2D DCT/IDCT: • Input Data: macro block (4x4 or 8x8) is read in (DCT). DCT coefficient matrix is read in (IDCT). • Column DCT/IDCT process: output to temporary registers that will be transposed for Row processing. • Row DCT/IDCT process: data read from temporary register which are processed column by column.

  10. DCT H/W Extension 3 of 5

  11. DCT H/W Extension 4 of 5 • Instruction set: • Load+computation+transfer to accumulator: ACy=copr(k8,ACx,Xmem,Ymem) • Computation+transfer to accumulator+memory write: ACy=copr(k8,ACx,ACy),Lmem=Acz • Special instructions: ACy=copr(k8,ACx,ACy) • Refer to application note for details and listings of macros realizing complete 8x8 DCT/IDCT.

  12. DCT H/W Extension 5 of 5 • H/W extensions can be used through C-callable functions provided by IMLIB

  13. Debug • To look at the internal register of the hardware extension … DCT and IDCT Hardware accelerator registers

  14. Tutorial DCT/IDCT with IMLIB • Describe step by step how to use H/W extensions with IMLIB. • Requires installation of IMLIB before continuing. • Requires special memory configuration to obtain optimum performance. • CCS allows display of image contained in DSP memory.

  15. Memory Configuration hwdct.cdb dct.cmd

  16. Display Input Image 1 of 2 • Load hwdct.pjt • Build and load application • Input image is « goldhill » 128x128 which is included by the header file (#include «imagesample.h») at the address goldhill • To have the internal memory initialized use Debug>go to main command. • You are now ready to display the input image using view>Graph>image

  17. Display Input Image 2 of 2

  18. In place DCT Computation   

  19. Actual dct.c Program     

  20. Output Display and Initialization

  21. Output Buffer Update

  22. References • JPEG for digital panel (SPRA664) • TMS320C55x Hardware extensions for image/video applications - Programmer’s reference (SPRU098) • TMS320C55x image/video processing library programmer’s reference (SPRU037)

More Related