New Irregular Sampling Coding Method for Transmitting Images

  • Slides: 18
Download presentation
New Irregular Sampling Coding Method for Transmitting Images Progressively Hung, K. -L. and Chang,

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 n n n Introduction Previous Works Proposed Method Experimental Result Conclusions

Outline n n n Introduction Previous Works Proposed Method Experimental Result Conclusions

Introduction n PIT(Progressive Image Transmission) techniques are used to send an image through many

Introduction n 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) Siden Coded by VQ Sender: 1 1 2 match Receiver 1

SMM(Side Match Method) Siden Coded by VQ Sender: 1 1 2 match Receiver 1 1 1 2 2 1 5 11 15 8 2 6 12 13 9 3 7 16 14 10 4 2 (sub-image: 3*3 ) R(K)=0. 056 8/(4*4*3*3) Transmission order 1 2 2

FRM(Fast Reconstruction Method) Sender CST Central Sampling Technique PCT Receiver 2 6 5 7

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

TSVQ(Tree-structure Vector Quantization) Sender Original image code table 0101 0011 0111 1101 0111 1001

TSVQ(Tree-structure Vector Quantization) Sender Original image code table 0101 0011 0111 1101 0111 1001 0111 0101 1101 0111 1101 0101 1011 0101 1001 0110 0101 0110 . . 1111 . . 1011 Receiver 0 phase 1 : 2 1 phase 2 : 5 1 phase 3 : 11 0 phase 4 : 22

TSVQ(cont. ) <step 1> 0 0 1 0 0 0 1 1 1 0

TSVQ(cont. ) <step 1> 0 0 1 0 0 0 1 1 1 0 0 0 . . 1 <step 2> 01 01 00 01 11 01 10 01 01 01 11 11 01 11 10 10 01 01 01 . . 10

SMTSVQ(Side-Match reconstruction method using TSVQ) n n An improvement of TSVQ Assume the depth

SMTSVQ(Side-Match reconstruction method using TSVQ) n n 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: n n Phase 1 to phase n/2 Phase ((n/2)+1) to phase n

SMTSVQ(cont. ) With TSVQ n n ? ? 0011 With TSVQ and side match

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

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

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

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

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

Selective Segmenting n n Step 1: The samples are divided into several segments. Step

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

Selective Segmenting(cont. ) n n Step 3: the original image is divided into non-overlapped

Selective Segmenting(cont. ) n n Step 3: the original image is divided into non-overlapped 4*4 blocks. Step 4: we defined sample segments to transform. n These pixel segment as

Selective Segmenting(cont. ) blocks of sampled image n 5 1 6 2 3 7

Selective Segmenting(cont. ) blocks of sampled image n 5 1 6 2 3 7 4 8 6 2 5 1 4 8 3 7 Sender: phase 1: phase 2: phase 3: phase 4: phase 5: …… …… 1 2 0 1 1 pixels pixel Block of original Image

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

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

Experimental Result---Bit rates

Experimental Result---Bit rates

Image Quality

Image Quality

Conclusions n n By our experimental results, the image quality is better than FRM,

Conclusions n n 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.