1 / 21

:

??????. ?. ???????? : <????> <?????> . . ????????????????,????????????????,?????,??????????(object-oriented)?????.. . ???(picture element, pixel)?????????,???????????(??????)??X,Y???R,G,B???. ????????????

channer
Télécharger la présentation

:

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. ???? (??????) ??:??? ??? ??? ??? ???

    2. ?????? ?. ???????? : <????> <?????>

    3. ?. ????: ???? ???? ???: ??????????????????.???dpi(dots per inch?pixels per inch)??. ????:Image Mode??????????????????????? ?.????????????. RGB CMYK Lab YUV&YIO Grayscale(????)??Graylevel---???256(8??)?????? ?????????????? Bitmap---?????????????????,??????bit?? ????????????? Duotone Indexed color ????

    4. ?. ??????: ????????????,???????????? ???Image Processing. ??? ???? ???? ???? ???? ???? ???? ???? ?? ?. ??????: SNR(signal-to-noise ratio) PSNR(peak-signal-to-noise ratio)

    5. ?????? ?. ?? ?. ??????: ????????????????????.?????????? ?:?????PCX?TGA?TIFF?GIF?JPEG?VQ?.??PCX?TIFF? TGA???????????????.GIF?JPEG????????? ??????????;??VQ,??????????.?PCX? GIF?TIFF??TGA????????????????.?????? ?????????????????,????????????? ??????????.??VQ?JPEG?????????????? ?.??????VQ?JPEG???????,??????????? ???????,???????????,??????????? ?????????????

    6. <?????????> 1. PCX ??????????Zsoft??????????,?????? ????(Run Length Encoding ,??RLE)????????,? ????????,???(Row by Row) ?????.?????? ???,?????????????????????????? ??????,???????????????????. 2. TGA ??AT&T???????????,???????????????? ??.???????????(Pixel)?????????,????? ????????????,?TGA ??????????????,? ?????????????????????.TGA ?????PCX?? ?????(????????)?????????????.

    7. 3. TIFF (Tagged Image File Format) ????????????????????????? Aldus Corporation?Aldus Developers?1986?????.?????(Tag)?????????,????????.??????????,TIFF ??????????: (1) ??????????????,??MS Windows?DOS?UNIX?OS/2 ?. (2) ????????,?????- ??- ?? ???(Lempel-Ziv- Welch Encoding,??LZW)???????(Huffman's Encoding)??????????;????????????,?? ???????? (3) ?????????,????????????????,TIFF? ???.??TIFF????????,?????????????? ??TIFF???????????,??TIFF?????????? ?.

    8. 4. GIF ?1987??Compu-serve??????????,??????????? ?- ??- ??????,????????(String Table) ????.? ????????????????????????,???????? ????????????????,???????????????? ???????,?GIF ?????????.??,GIF ???????- ??- ????????????- ??- ???,????????? ?,???????- ??- ?????????????:GIF ???- ??- ??????????????????,??????????? ??????,?????????????,????????

    9. 1. JPEG(Joint Photographic Coding Expert Group) ???????(International Organization for Standardization,?? ISO)????????????(International Telegraph and Telephone Consultative Committee,??CCITT)??????????????,? ????????????.JPEC ?????(Lossy) ??????,?? ???????(Discrete Cosine Transform,??DCT)???????? ???????,????????,??????????.???JPEC ?????????????,???JPEG ?????????????? ??;????,????(??????????????????)?5% ~15%???,JPEC?????????????,??????????? ?????.JPEG???????,????????????.????JPEG ???JFIF(JPEG File Interchange Format).??JPEG ?????,?? ???????,???????????????.JPEG ??????? ???8 ???????.????,????????????????? ???JPEG ???. <?????????>

    10. 2. VQ (Vector Quantization) ???????????????.????????????(??JPEG) ????VQ?????;??,??VQ???????????????? ???????,?VQ????????????????????.??VQ ??????????????????????????.??????? ?????(Code book),?????????????(????)???? (Code word).??,????????????????,?????? ?,??????????.???????VQ??????,?????? ??????????????????,?VQ ?????????.?? ???256??????????,VQ????????????(?6%).? ?????,??VQ ???????????????????????? ??????,??????????.???????????????? ???????,???????.

    11. <?????> ?????????,???????,??????? ??????????????????????,?? ????????

    12. ?. ????????????? <?> ?????????? ????????????????????,??,??????????????. ??????: ?????? ? ?????? ? DCT?? ? ??? ? ??? ? ???? ??????????: (?)????/?????????????. (?)????????????. (?)???????????????. ?????????(Compression) ????,??????? (Decompression)????.???????????:???? ???????,??????????? .

    14. 1. RASTER -> BLOCK ?????????? ???(block) ?????.??????????????????. 2. RGB -> YUV ????????(??)???(R)??(G)??(B)??????,?????????????(Luminance)Y??????? (Chrominance)U?V.??????: Y = 77/256R + 150/256G + 29/256B U = -44/256R - 87/256G + 131/256B + 128 V = 131/256R - 110/256G - 21/256B + 128

    15. 3. DCT (Discrete Cosine Transform;??????) ?????????? 8 x 8 ??,????8 x 8??? (coefficients).????????????(space domain)???? ????(frequency domain),??8 x 8???????????? ????,????????,??????,?????????. ????,????????????????,????????? ????????????,??????????????.??? ????????(quantization)??,????????????? 0.??????????????????????????,????????:????.?????????????,?????? ?????????????.????????????,?75%?? ????????????. 4. QUANTIZATION ?????(quantization)???????(linear quantization)???,?????????????????.

    16. 5. RUN LENGTH ENCODE ??????,??8 x 8??????????????? ????? ?????0.?????0???????,???8 x 8??????? ??? (zigzag scan ),????????.???????,???? ?????? (run length encode),????????. 6. HUFFMAN ENCODE ???????????(Huffman coding)??????????.?? ?????????:????????????????,???? ????????????,?????????????. ????JPEG????????:??????RGB??????????DCT(Discrete Cosine transform)??,???????”????”?????,????????(??????JPEG???????), ?????????,???????????,????????,??????????,?????Huffman???????,????,??JPEG??.????????????.

    17. <?> ???????? 1.??????????: Run Length Encoding(RLE)---- ???:???,???????????. ???????????????,????????????????. LZW(Lempel-Ziv-Welch)Coding---- ????????GIF(Graphics Interchange Format)??TIFF(Tag lmage File Format)??????? ??.???????????????,?????????????? ?,?????????????,?????????.??????? ????????,?????????????????. Huffman Coding ??????(Huffman’s Encode)---- ?????1952??????????????,?????????? ?,????,????????????(Single Character)???? ?,????,????????(Huffman’s Tree).???????, ?0?1????,???????,?????????,??????? ?????,???Huffman’s tree ,???????.

    18. ??????????????????????????????.? ????????????????????,??????????? ????????????????????????????. ??????(Arithmetic Coding)---- ?Rissanen ?1979?????????? ?,??????????????????????,??????? ??????? ???????(Predictive Coding),??..

    19. 1.??????????: DCT (Discrete Cosine Transform)???????????---- ????? ???????????????.DCT????????,?JPEG?? ??????.DCT???????,??DCT??????????,? ???DCT??????????????????. Quantization???(??)??---- ?????????????. ??(WAVELET)??---- WAVELET????????????????.???????????????????.????,????????????????,??????????????????,???????????,??????????????????.????????(Fourier)???????,???????????,?????????.????????,????????????.?????????1960??????????,???????????????,?????????????,???????????,????????????.

    20. WAVELET????????????,??????????????,? ???????????????,????????,???????? ????.??????????,?????,?????????(? ???????).?????????????,?????????, ??????????????????,?????????????? ??.??WAVELET?????????????lossless???????? ???????,??????????????????,?????? ????????????,?????????????.?????? ???????????????,??????????,?????? ??,???????????,????????.????WAVELET?? ??????. ?????????: jpeg????????????,?jpeg2000??jpeg??? ?,?jpeg2000???DCT?????????????wavelet,?DCT? ?mpeg??????????,?DCT?????????. ? ? ? ? ( Perceptual coding ) ?????? (Vector quantization) ????? (Transfer coding) ?????(Subband coding)

    21. ????????? 1. ???????????????????? 2. ???????????????????????? 3. ???????????? 4. ??????????? 5. ???????????????

More Related