BRONZE
BRONZE ๋“ฑ๊ธ‰์˜ ํŒ๋งค์ž ์ž๋ฃŒ

์˜์ƒ์ฒ˜๋้ฉ์— ๋Œ€ํ•œ ๊ธฐ๋ณธ์ ์ธ ๊ฐœ๋… ๋ฐ ์งˆ๋ฌธ๊ณผ ๋‹ต3

์˜์ƒ์ฒ˜๋้ฉ์—์„œ ์“ฐ์ด๋Š” ์—ฌ๋Ÿฌ๊ฐ€์ง€ ํ•˜์œ„ ๊ฐœ๋…์„ ์„ค๋ช…ํ•˜์˜€์Šต๋‹ˆ๋‹ค. 1.DCT์™ฟ’ DFT์˜ ๊ด€๊ณ„, Block-DCT์˜ ์žฅ์  2. Aliasing ํ˜„์ƒ, Blocking artifact, Ringing effect ์„ค๋ช… ์™œ ringing effect๋Š” ์ฃผํŒŒ์ˆ˜ ๋„๋ฉ”์ธ ํ•„ํ„ฐ์—์„œ๋งŒ ์ผ์–ด๋‚˜๋Š”๊ฐ€ 3. JPEG, JPEG2000 ์„ค๋ช… 4.MPEG ์„ค๋ช… 5.์–‘์žํ™” ์„ค๋ช…, quantization
10 ํŽ˜์ด์งฟ’
์›Œ๋“œ
์ตœ์ดˆ๋“ฑ๋ก์ผ 2010.05.28 ์ตœ์ข…์ ฟ’์ž‘์ผ 2010.04
10P ๋ฏธ๋้ฉ๋ณด๊ธฐ
์˜์ƒ์ฒ˜๋้ฉ์— ๋Œ€ํ•œ ๊ธฐ๋ณธ์ ์ธ ๊ฐœ๋… ๋ฐ ์งˆ๋ฌธ๊ณผ ๋‹ต3
  • ๋ฏธ๋้ฉ๋ณด๊ธฐ

    ์†Œ๊ฐœ

    ์˜์ƒ์ฒ˜๋้ฉ์—์„œ ์“ฐ์ด๋Š” ์—ฌ๋Ÿฌ๊ฐ€์ง€ ํ•˜์œ„ ๊ฐœ๋…์„ ์„ค๋ช…ํ•˜์˜€์Šต๋‹ˆ๋‹ค.
    1.DCT์™ฟ’ DFT์˜ ๊ด€๊ณ„, Block-DCT์˜ ์žฅ์ 
    2. Aliasing ํ˜„์ƒ, Blocking artifact, Ringing effect ์„ค๋ช…
    ์™œ ringing effect๋Š” ์ฃผํŒŒ์ˆ˜ ๋„๋ฉ”์ธ ํ•„ํ„ฐ์—์„œ๋งŒ ์ผ์–ด๋‚˜๋Š”๊ฐ€
    3. JPEG, JPEG2000 ์„ค๋ช…
    4.MPEG ์„ค๋ช…
    5.์–‘์žํ™” ์„ค๋ช…, quantization

    ๋ชฉ์ฐจ

    1. Explain the relationship between DCT and DFT. Explain FFT(Fast Fourier Transform) and block-DCT which are widely used in many signal processing applications. Describe the merits and demerits of block-DCT compared to DCT
    2. Explain aliasing phenomenon, blocking artifact and ringing artifact. Explain why the ringing effect occurs when using the frequency domain filter while it does not occur when using the spatial domain filter
    3. Investigate still image compression standards (JPEG, JPEG2000) and summary their characteristics.
    4. Investigate the video compression techniques and describe the difference between the still image compression and video compression.
    5. Investigate the quantization process in signal processing

    ๋ณธ๋ๅฉ๋‚ด์šฉ

    1. Explain the relationship between DCT and DFT. Explain FFT(Fast Fourier Transform) and block-DCT which are widely used in many signal processing applications. Describe the merits and demerits of block-DCT compared to DCT.
    โ‘ DCT์™ฟ’ DFT์˜ ๊ด€๊ณ„
    DCT๋Š” ๊ธฐ๋ณธ์ ์œผ๋กœ DFT์—์„œ ํŒŒ์ƒ๋˜์—ˆ์ง€๋งŒ, ๋ช‡ ๊ฐ€์ง€ ์ฐจ์ด์ ์„ ๋ณด์ธ๋‹ค. ์šฐ์„ , DFT๊ฐ€ Real๊ฐ’๊ณผ Imaginary๋ฅผ ๊ฐ€์ง€๋Š” Complex์˜ ํ˜•ํƒœ๋กœ ๋‚˜ํƒ€๋‚˜๋Š” ๊ฒƒ์— ๋น„ํ•ด์„œ DCT๋Š” cosine๊ฐ’์œผ๋กœ ๋‚˜ํƒ€๋‚˜๋Š” Real๊ฐ’๋งŒ์„ ๋‹ค๋ฃจ๊ธฐ ๋•Œ๋ฌธ์— ์—ฐ์‚ฐ๋Ÿ‰์ด ์ ๊ณ , ๊ทธ๋ž˜ํ”„๋กœ ํ‘œ์‹œํ•˜๊ธฐ๊ฐ€ ์ˆ˜์›”ํ•˜๋‹ค.
    DFT์—์„œ DCT๋ฅผ ์œ ๋„ํ•˜๋Š” ๋ฐฉ๋ฒ•์€, ์•„๋ž˜์˜ ์‹๊ณผ ๊ฐ™๋‹ค.

    2N-point DFT์—์„œ ์‹ค์ˆ˜์˜์—ญ ๋ถ€๋ถ„๋งŒ ๊ณ ๋ คํ•ด์„œ DCT ์–ป๋Š” ๊ฒƒ์€ ์•„๋ž˜์™ฟ’ ๊ฐ™์ด ํ•˜๋ฉด ๋œ๋‹ค.

    DCT๋Š” ๋‹จ์ง€ ์‹ค์ˆ˜๋กœ๋งŒ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๊ธฐ ๋•Œ๋ฌธ์—, DFT๋Š” DCT๋ฅผ mirroring ํ•œ ๊ฒƒ๊ณผ ๊ฐ™์€ ํ˜•์ƒ์„ ๊ฐ€์ง„๋‹ค. ์—ฌ๊ธฐ์„œ DFT๋Š” ์‹ค์ˆ˜ ๋ถ€๋ถ„๊ณผ ํ—ˆ์ˆ˜ ๋ถ€๋ถ„์„ ๋ชจ๋‘ ๊ฐ€์ง€๊ณ  ์žˆ๋Š” ๋ณต์†Œ์ˆ˜ ํ˜•ํƒœ์ด๋‹ค. ๊ทธ๋ฆฌ๊ณ  even-symmetry๋ฅผ ๊ฐ–๋Š” data์— ์ ์šฉ๋˜์–ด, DCT๋ฅผ mirroringํ•˜์—ฌ DFT๋ฅผ ์–ป๋Š”๋‹ค.

    โ‘กFFT (Fast Fourier Transform)
    DFT๋ฅผ ๊ตฌํ˜„ํ•˜๋Š”๋ฐ ์žˆ์–ด์„œ N๊ฐœ์˜ sample์— ๋Œ€ํ•ด ํ•˜๋‚˜๋‹น N๋ฒˆ์˜ ์—ฐ์‚ฐ์„ ํ•ด์•ผ ํ•˜๋ฏ€๋กœ O(N^2)์˜ complexity๊ฐ€ ์š”๊ตฌ๋œ๋‹ค. ๋ณธ ์‹คํ—˜์—์„œ๋Š” 256*256 size์˜ image๋ฅผ ๋‹ค๋ฃจ๋ฏ€๋กœ ๋งŽ์€ ์–‘์˜ sample์— ๋Œ€ํ•ด์„œ ์—ฐ์‚ฐ์„ ์ˆ˜ํ–‰ํ•ด์•ผ ํ•œ๋‹ค. Image์˜ ๊ฒฝ์šฐ DFT๊ฐ€ x์ถ•, y์ถ•์œผ๋กœ ๊ฐ๊ฐ ํ•œ ๋ฒˆ์”ฉ ํ•ด์•ผ ํ•˜๋ฏ€๋กœ ๊ฐ€๋กœ์„ธ๋กœ sample์˜ ์ˆ˜๊ฐ€ ๊ฐ™๋‹ค๋ฉด ์ด O(N^4)์˜ complexity๊ฐ€ ์š”๊ตฌ๋œ๋‹ค.

    ์ฐธ๊ณ ์ž๋ฃŒ

    ยท ์—†์Œ
  • ์ž๋ฃŒํ›„๊ธฐ

    Ai ๋ฆฌ๋ทฐ
    ์งฟ’์‹ํŒ๋งค์ž์˜ ์ด ์ž๋ฃŒ๋Š” ๊ณผ์ œ๋ฅผ ์ž‘์„ฑํ•˜๋Š” ๋ฐ ํ•„์š”ํ•œ ์ •๋ณด๋ฅผ ์™„๋ฒฝํ•˜๊ฒŒ ์ถฉ์กฑ์‹œ์ผœ์ฃผ์—ˆ์Šต๋‹ˆ๋‹ค. ๋•๋ถ„์— ๊ณผ์ œ ์ œ์ถœ ๊ธฐํ•œ์„ ๋งž์ถœ ์ˆ˜ ์žˆ์–ด ์ •๋ง ๊ฐ์‚ฌํ–ˆ์Šต๋‹ˆ๋‹ค.
    • ์ž์ฃผ๋ฌป๋Š”์งˆ๋ๅฉ์˜ ๋‹ต๋ณ€์„ ํ™•์ธํ•ด ์ฃผ์„ธ์š”

      ํ•ดํ”ผ์บ ํผ์Šค FAQ ๋”๋ต–๊ธฐ

      ๊ผญ ์•Œ์•„์ฃผ์„ธ์š”

      • ์ž๋ฃŒ์˜ ์ •๋ณด ๋ฐ ๋‚ด์šฉ์˜ ์ง„์‹ค์„ฑ์— ๋Œ€ํ•˜์—ฌ ํ•ดํ”ผ์บ ํผ์Šค๋Š” ๋ณด์ฆํ•˜์ง€ ์•Š์œผ๋ฉฐ, ํ•ด๋‹น ์ •๋ณด ๋ฐ ๊ฒŒ์‹œ๋ฌผ ์ €์ž‘๊ถŒ๊ณผ ๊ธฐํƒ€ ๋ฒ•์  ์ฑ…์ž„์€ ์ž๋ฃŒ ๋“ฑ๋ก์ž์—๊ฒŒ ์žˆ์Šต๋‹ˆ๋‹ค.
        ์ž๋ฃŒ ๋ฐ ๊ฒŒ์‹œ๋ฌผ ๋‚ด์šฉ์˜ ๋ถˆ๋ฒ•์  ์ด์šฉ, ๋ฌด๋‹จ ์ „์žฌโˆ™๋ฐฐํฌ๋Š” ๊ธˆ์ง€๋˜์–ด ์žˆ์Šต๋‹ˆ๋‹ค.
        ์ €์ž‘๊ถŒ์นจํ•ด, ๋ช…์˜ˆํ›ผ์† ๋“ฑ ๋ถ„์Ÿ ์š”์†Œ ๋ฐœ๊ฒฌ ์‹œ ๊ณ ๊ฐ๋น„๋ฐ”์นด์ง€๋…ธ Viva์˜ ์ €์ž‘๊ถŒ์นจํ•ด ์‹ ๊ณ ๋น„๋ฐ”์นด์ง€๋…ธ Viva๋ฅผ ์ด์šฉํ•ด ์ฃผ์‹œ๊ธฐ ๋ฐ”๋ž๋‹ˆ๋‹ค.
      • ํ•ดํ”ผ์บ ํผ์Šค๋Š” ๊ตฌ๋งค์ž์™ฟ’ ํŒ๋งค์ž ๋ชจ๋‘๊ฐ€ ๋งŒ์กฑํ•˜๋Š” ์„œ๋น„์Šค๊ฐ€ ๋˜๋„๋ก ๋…ธ๋ ฅํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ์•„๋ž˜์˜ 4๊ฐ€์ง€ ์ž๋ฃŒํ™˜๋ถˆ ์กฐ๊ฑด์„ ๊ผญ ํ™•์ธํ•ด์ฃผ์‹œ๊ธฐ ๋ฐ”๋ž๋‹ˆ๋‹ค.
        ํŒŒ์ผ์˜ค๋ฅ˜ ์ค‘๋ณต์ž๋ฃŒ ์ €์ž‘๊ถŒ ์—†์Œ ์„ค๋ช…๊ณผ ์‹ค์ œ ๋‚ด์šฉ ๋ถˆ์ผ์น˜
        ํŒŒ์ผ์˜ ๋‹ค์šด๋กœ๋“œ๊ฐ€ ์ œ๋Œ€๋กœ ๋˜์ง€ ์•Š๊ฑฐ๋‚˜ ํŒŒ์ผํ˜•์‹์— ๋งž๋Š” ํ”„๋กœ๊ทธ๋žจ์œผ๋กœ ์ •์ƒ ์ž‘๋™ํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ ๋‹ค๋ฅธ ์ž๋ฃŒ์™ฟ’ 70% ์ด์ƒ ๋‚ด์šฉ์ด ์ผ์น˜ํ•˜๋Š” ๊ฒฝ์šฐ (์ค‘๋ณต์ž„์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋Š” ๊ทผ๊ฑฐ ํ•„์š”ํ•จ) ์ธํ„ฐ๋„ท์˜ ๋‹ค๋ฅธ ์‚ฌ์ดํŠธ, ์—ฐ๊ตฌ๊ธฐ๊ด€, ํ•™๊ป“, ์„œ์  ๋“ฑ์˜ ์ž๋ฃŒ๋ฅผ ๋„์šฉํ•œ ๊ฒฝ์šฐ ์ž๋ฃŒ์˜ ์„ค๋ช…๊ณผ ์‹ค์ œ ์ž๋ฃŒ์˜ ๋‚ด์šฉ์ด ์ผ์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ

    ํ•จ๊ป˜ ๊ตฌ๋งคํ•œ ์ž๋ฃŒ๋„ ํ™•์ธํ•ด ๋ณด์„ธ์š”!

    ์ฐพ์œผ์‹œ๋˜ ์ž๋ฃŒ๊ฐ€ ์•„๋‹Œ๊ฐ€์š”?

    ์ง€๊ธˆ ๋ณด๋Š” ์ž๋ฃŒ์™ฟ’ ์—ฐ๊ด€๋˜์–ด ์žˆ์–ด์š”!
    ์™ผ์ชฝ ํ™”์‚ดํ‘œ
    ์˜ค๋ฅธ์ชฝ ํ™”์‚ดํ‘œ
    ๋ฌธ์„œ ์ดˆ์•ˆ์„ ์ƒ์„ฑํ•ด์ฃผ๋Š” EasyAI
    ์•ˆ๋…•ํ•˜์„ธ์š”. ํ•ดํ”ผ์บ ํผ์Šค์˜ ๋ฐฉ๋Œ€ํ•œ ์ž๋ฃŒ ์ค‘์—์„œ ์„ ๋ณ„ํ•˜์—ฌ ๋‹น์‹ ๋งŒ์˜ ์ดˆ์•ˆ์„ ๋งŒ๋“ค์–ด์ฃผ๋Š” EasyAI ์ž…๋‹ˆ๋‹ค.
    ์ €๋Š” ์•„๋ž˜์™ฟ’ ๊ฐ™์ด ์ž‘์—…์„ ๋„์™ฟ’๋“œ๋ฆฝ๋‹ˆ๋‹ค.
    - ์ฃผ์ œ๋งŒ ์ž…๋ ฅํ•˜๋ฉด ๋ชฉ์ฐจ๋ถ€ํ„ฐ ๋ณธ๋ๅฉ๋‚ด์šฉ๊นŒ์ง€ ์ž๋™ ์ƒ์„ฑํ•ด ๋“œ๋ฆฝ๋‹ˆ๋‹ค.
    - ์žฅ๋ฌธ์˜ ์ฝ˜ํ…์ธ ๋ฅผ ์‰ฝ๊ณ  ๋น ๋ฅด๊ฒŒ ์ž‘์„ฑํ•ด ๋“œ๋ฆฝ๋‹ˆ๋‹ค.
    - ์Šคํ† ์–ด์—์„œ ๋ฌด๋ฃŒ ์บ์‹œ๋ฅผ ๊ณ„์ •๋ณ„๋กœ 1ํšŒ ๋ฐœ๊ธ‰ ๋ฐ›์„ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. ์ง€๊ธˆ ๋ฐ”๋กœ ์ฒดํ—˜ํ•ด ๋ณด์„ธ์š”!
    ์ด๋Ÿฐ ์ฃผ์ œ๋“ค์„ ์ž…๋ ฅํ•ด ๋ณด์„ธ์š”.
    - ์œ ์•„์—๊ฒŒ ์ ํ•ฉํ•œ ๋ฌธํ•™์ž‘ํ’ˆ์˜ ๊ธฐ์ค€๊ณผ ํŠน์„ฑ
    - ํ•œ๊ตญ์ธ์˜ ๊ฐ€์น˜๊ด€ ์ค‘์—์„œ ์ •์‹ ์  ๊ฐ€์น˜๊ด€์„ ์ด๋ฃจ๋Š” ๊ฒƒ๋“ค์„ ๋ฌธํ™”์  ๋ฌธ๋ฒ•์œผ๋กœ ์ •๋ฆฌํ•˜๊ณ , ํ˜„๋Œ€ํ•œ๊ตญ์‚ฌํšŒ์—์„œ ์ผ์–ด๋‚˜๋Š” ์‚ฌ๊ฑด๊ณผ ์‚ฌ๊ณ ๋ฅผ ๋น„๊ตํ•˜์—ฌ ์ž์‹ ์˜ ์˜๊ฒฌ์œผ๋กœ ๊ธฐ์ˆ ํ•˜์„ธ์š”
    - ์ž‘๋ณ„์ธ์‚ฌ ๋…ํ›„๊ฐ
    ํ•ด์บ  AI ์ฑ—๋ด‡๊ณผ ๋Œ€ํ™”ํ•˜๊ธฐ
    ์ฑ—๋ด‡์œผ๋กœ ๊ฐ„ํŽธํ•˜๊ฒŒ ์ƒ๋‹ดํ•ด๋ณด์„ธ์š”.
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    AI ์ฑ—๋ด‡
    ์•ˆ๋…•ํ•˜์„ธ์š”. ํ•ดํ”ผ์บ ํผ์Šค AI ์ฑ—๋ด‡์ž…๋‹ˆ๋‹ค. ๋ฌด์—‡์ด ๊ถ๊ธˆํ•˜์‹ ๊ฐ€์š”?
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