DesignCon A New Reference Design Development Environment for JPEG 2000 Applications

Transcription

1 DesignCn 2003 System-n-Chip and ASIC Design Cnference Reference Design Paper A New Reference Design Develpment Envirnment fr JPEG 2000 Applicatins Authrs Bill Finch Vice President, CAST Inc. Warren Miller Vice President, Avnet Design Services

2 Abstract The newest revisins t standards fr vide prcessing, like JPEG and MPEG are becming available and are expected t create new applicatins and markets. Hardware implementatins f these standards will be available first in the frm f IP Cres fr FPGAs. A reference design based n a Xilinx FPGA develpment bard frm Avnet Design Services and IP Cres frm CAST have been cmbined t create a reference design fr the newest versins f the JPEG and MPEG standards. The paper will describe the features and functinality f the design as well as the size, perfrmance and cst f the final circuit bard implementatin. This Reference Design will be demnstrated in the Reference Design Village. Authrs Bigraphies Bill Finch Bill attended Purdue University where he received a BSEE in Out f Purdue he jined GenRad, Inc. as a sales engineer and rse thrugh the sales ranks t becme US Sales Manager in Tw years later he became Prduct Line Manager fr a new prduct in functinal testing f micrprcessrs. Mr. Finch held a variety f executive psitins at GenRad in prduct management and marketing until he left in 1995 t jin Breas, Inc., a start-up in the field f Supercnductivity. He has been VP f Sales and Service fr SemiTest, Inc., a supplier f metrlgy tls t semicnductr firms such as Intel and Mtrla. He was President and General Manager f the Surface Inspectin Systems divisin f Brwn and Sharpe that specialized in defect detectin in semicnductrs and flat panel displays. He has been vice President f Sales fr CAST fr the last tw years. Warren Miller Warren is Vice President f Marketing and Hnrary Chief Engineer at Avnet Design Services. He is respnsible fr managing the centralized applicatins design center, technical marketing and business planning effrts fr Avnet Design Services, the technical arm f Avnet Cilicn, the premier technical distributr f cmplex semicnductr prducts. Warren has wrked in the electrnics industry fr ver 20 years as a design engineer, applicatins engineer, and Directr f Engineering as well as in marketing, s he can bth cde in and spell VHDL.

3 Intrductin The ability t send images f all sizes and types quickly frm Pint A t Pint B has lng been viewed as ne f majr benefits f high-speed netwrks and the Internet. Hwever, in spite f the huge advances in cmpute pwer and netwrk bandwidth, we are still shrt f realizing the gal. Large, cmplex images still defy us if we want t get a true recnstructin f the riginal at the receiving end withut tying up ur netwrks fr lng perids. We still need t manage multiple frmats and supprt multiple tls t encde and decde these frmats. The ability t manipulate the image during transmissin is ttally missing. With the publishing f the JPEG 2000 standard in 2001, we are nw much clser t achieving ur gals. JPEG 2000 is a single standard that allws fr highly scalable applicatins aimed at satisfying mst users. The advantages f the new standard are: Better image quality at the same file size 25-35% smaller file sizes at cmparable image quality Gd image quality even at very high cmpressin ratis, ver 80:1 Lw cmplexity ptin fr devices with limited resurces such as cellphnes Scalable image files -- n decmpressin needed fr refrmatting. With JPEG 2000, the image that best matches the target device can be extracted frm a single cmpressed file n a server. Optins include: i. Image sizes frm thumbnail t full size ii. Grayscale t full 3 channel clr (there is n limitatin in the number f clr channels e.g. there are satellite images with 4 and mre lr channels) iii. Lw quality image t lssless (identical t riginal image) Prgressive rendering and transmissin thrugh a layered image file structure. Example: frm a single 100 KByte image file f a 512x512 riginal image, a lw reslutin 32x32 pixel thumbnail image can be transmitted by sending nly 10Kbytes. Sending an additinal 15 KBytes increases the reslutin t 64x64 pixels, and s n. Other layerings prvide fr prgressive transmissin and rendering based n quality, clr cmpnent and spatial lcatin in the image. With these tremendus advantages an increasing number f designers will be develping applicatins using these standards, but the design engineer may nt have a lt f time t d the detailed design and cmpliance testing- they may need a reference design platfrm and intellectual prperty that can leverage design time. This paper will describe just such a reference design. JPEG2000 Applicatin Descriptin The big differences with past cmpressin techniques are in the use f Discrete Wavelet Transfrms t de-crrelate the image prir t cmpressin and the ability t have multiple entrpy cders (the real cmpressin engine) t achieve high thrughput. Mst f the bttleneck in the past has been in the entrpy cders. Apprximately 70% f the time spent encding an image is in this phase. The ability t separate the actual bit stream frm the data abut the cnstructin f the bit stream is critical t the ability t manipulate the image as desired with ut changing the underlying stred image itself. By cntrlling parameters such as the type f filtering dne in the DWT and the quantizatin levels, we can achieve everything frm lssless transmissin at lw cmpressin ratis t lssy transmissin with very high cmpressin (200:1) while still cntrlling image quality.

4 Given the number f factrs invlved, it is imprtant t cnsider the fllwing key trade-ffs in a design. Thrughput required, Image size(s) t be prcessed, Image cmpsitin (clr, mn, etc.), Lssy vs. lssless, Implementatin technlgy- FPGA vs. ASIC, and Memry Nw let s cnsider sme specific types f real wrld design trade-ffs, but first lets prvide a few mre definitins. Quantizatin This setting allws yu t thrw away the least significant bits f the transfrmed image. It basically cntrls speed vs. reslutin. Bit rate cntrl This is an algrithm that selects which part f a cmpressed image needs t be transmitted fr ptimum image recnstructin assuming there are bandwidth limitatins which dn t allw the transmissin f the whle cmpressed image. Errr resiliency Mechanisms are built in t the standard t allw recvery frm errrs in transmissin. This is especially imprtant in nisy transmissins, e.g. wireless. Nw fr the trade-ffs: Speed vs Area (and memry requirements)! The standard allws fr cde-blcks t be entrpy-cded / decded separately. Therefre, parallel entrpy cding engines can be emplyed t increase speed. This cmes, f curse, at the cst f extra memry and area (gatecunt). Speed vs ptimal bit-rate cntrl! The time spend in entrpy cding (which is a large fractin f the ttal encding time) can be reduced if less data are fed fr entrpy cding. This can be achieved by using higher quantizatin values. Hwever, the bigger the quantizatin values are, the smaller the ptimizatin field is left fr the bit-rate cntrl algrithm. Prgrammability vs Area! Hardwiring the DWT filter type (5/3 r 9/7), the quantizatin tables, and the entrpy cding switches can help t reduce the area requirements. Errr resilience vs Cmpressin efficiency (bandwidth)! Errr resilience mechanisms intrduce small verheads in the final stream size. Reference Design Platfrm Given the number f issues fr a designer t cnsider and the fact that the standard is still relatively new, the need fr a rbust but easy t use develpment envirnment becmes bvius. It is much easier fr a design engineer t learn abut JPEG 2000 and experiment with the effects f the varius trade-ffs using real wrld images and live hardware. Designs get t market faster and with less effrt. CAST, Inc. has teamed with Avnet Design Services t bring t market just such a reference design and develpment envirnment based n the CAST JPEG 2000 IP cre and the Avaln reference design bards frm Avnet. Figure 1 shws a blck diagram f the JPEG2000 IP Cre frm CAST. The cre implements all the key elements f the JPEG2000 standard. The primary interfaces are the pixel interface, the buffer memry interface and the hst interface. Inside the cre are the DWT engine, the entrpy cding engines and the required supprt lgic fr cntrl, arbitratin and quantizatin. A hardware develpment bard fr

5 Avnet Design Services, shwn in figure 2, can be used t demnstrate the functinality f the JPEG2000 IP cre. Cntrl Unit Cnfiguratin Registers Cde-Blcks Memry Entrpy Cding Engine n Stream FIFO n Attributes FIFO n Pixel In I/F Level Shifter DWT Engine Quantizer/ Slicer Arbiter Entrpy Cding Engine 2 Stream FIFO 2 Attributes FIFO 2 HOST I/F SRAM I/F Entrpy Cding Engine n Stream FIFO 1 Attributes FIFO 1 Image Buffer (DP SRAM) Figure 1: JPEG2000 IP Cre frm CAST Blck Diagram The Virtex II based develpment bard prvides an ideal platfrm fr develping cmplex, high perfrmance designs. It ffers a huge FPGA with mre than sufficient amunts f internal (high-speed) memry. It ffers easily expanded external memry that can be used fr the nn-time-critical buffering. Figure 3: Demnstratin Applicatin- JPEG2000

6 It ffers a high-speed link t the hst CPU thrugh a PCI bus interface. Lastly, fr live data input it ffers a generic vide interface via a daughter bard. Other Avaln ptins exist fr different types f applicatins fr the cre, but since mst f the time engineers want t push the envelp f the technlgy, we chse the Virtex II. All f this backed by excellent supprt makes the chice a simple ne. Ordering Infrmatin The JPEG2000 IP Cre and Virtex-II develpment bard can be rdered frm Avnet Design Services. Fr infrmatin n price and delivery visit the ADS web page at