New Irregular Sampling Coding Method for Transmitting Images Progressively Hung, K.-L. and Chang, C.-C., IEE Image and Signal Processing, vol.150, no.1, Feb 2003, pp.44 -50 Advisor ：Chang, Chin-Chen Reporter： Lee, Jiau-Yun Date ：2003/5/6

Outline Introduction Previous Works Proposed Method Experimental Result Conclusions

Introduction PIT(Progressive Image Transmission) techniques are used to send an image through many stages. The receiver is given only a few bits to achieve a rough. Image quality is refined gradually.

SMM(Side Match Method) Coded by VQ Sender: Receiver 1 2 1 1 2 1 5 11 15 8 2 6 12 13 9 3 7 16 14 10 4 (sub-image:3*3 ) R(K)=0.056 8/(4*4*3*3) Transmission order

FRM(Fast Reconstruction Method) Sender Receiver CST Central Sampling Technique 2 6 5 7 1 8 4 9 3 1 <Pixel copy> 2 1 PCT Pixels Copy Technique 12 23 4 45 42 19 27 21 34 26 35

TSVQ(Tree-structure Vector Quantization) Sender Receiver 0 phase1 :2 1 phase2 : 5 1 phase3 : 11 0 phase4 : 22 Original image code table 0101 0011 0111 1101 1001 1011 0110 .. 1111

TSVQ(cont.) <step1> 1 .. <step2> 01 00 11 10 ..

SMTSVQ(Side-Match reconstruction method using TSVQ) An improvement of TSVQ Assume the depth of the codebook tree is n. We have n phases in the whole process. It can brake the process into two parts: Phase 1 to phase n/2 Phase ((n/2)+1) to phase n

SMTSVQ(cont.) Phase one: Phase two: With TSVQ and side match 01?? ???? 00?? 11?? 0101 ???? 0011 0111 1101 0110 With TSVQ 0101 01?? 0011 10?? 0111 1101 11?? 0110 0101 0011 0110 1000 0111 1101 1110 1100 1001

Proposed Method To evaluate an m*m mask. (centered in(i,j)) To divide different grids

Proposed Method(cont.) Original image Using the irregular sampling algorithm(n=3)

Selective Segmenting Step1:The samples are divided into several segments. Step2:The number of transmission phase is s(the power of 2) s=2 s=4 s=8 2 1 3 1 2 4 5 1 6 2 3 7 4 8

Selective Segmenting(cont.) Step3:the original image is divided into non-overlapped 4*4 blocks. Step4:we defined sample segments to transform. These pixel segment as

Selective Segmenting(cont.) Block of originalImage 5 1 6 2 3 7 4 8 Sender: phase1: 1 pixel phase2: 2 pixels phase3: 0 pixel phase4: 1 pixel phase5: 1 pixel …… blocks of sampledimage

The Further Encoding Technique Pixel value Huffman coding quantisation DPCM Sample segments output Position info. arithmetic coding

Experimental Result---Bit rates

Image Quality

Conclusions By our experimental results,the image quality is better than FRM,TSVQ and SMTSVQ. the higher bit rate requirement will be reduced by increasing the number of transmission phases.