Ẩn dữ liệu Các phương pháp trên ảnh

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cimtn hiunh Cc khng gian mu

Cc php tncng trn nh Cc phngphp ADL trn nh

Cc o

Hngpht trin

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1 bit

nhnhphn

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1 bit

nhnhphn

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1 bit 8 bits

nhnhphn nhxm

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1 bit 8 bits

nhnhphn nhxm nhmu

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1 bit 8 bits 24 bits

nhnhphn nhxm nhmu

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RGB

Red-Green-Blue

Hinth

CMYK

Cyan-Magenta-Yellow(Black)

In n

HSV

Hue- Saturation-Value

Datrn nntngtrcgic

Xl nh

YIQ

Luma- inphase-quadrature

Truynhnh, xl nh

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Dng trong cc hthngintmy tnh

R, G, B: [0, 255]

sRGB, Adobe RGB v Adobe Wide Gamut RGB

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L khng gian mu in 4 mu

Dng trong cc hthngin n

Spot color, CMYKOG, CcMmYK

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B

G

R

Y

M

C

1

1

1

Y

M

C

B

G

R

1

1

1

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ValueSaturation

Hue

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Thhinmiquan hcacc mu chnh xc hn

H: 003600;

S, V: 01

HSL, HSB

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Y = 0.5

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nhdngnhqut:

JPEG/JFIF, Exif,TIFF, RAW, PNG,

GIF, BMP, PPM,PGM, PBM, PNM

nhvector: CGM,SVG, vvv

nh3D: PNS, JPS,MPO

Kiunn

Nn khng mtmt:ABO, GIF, JBIG, ,

PGF, PNG, TIFF

Nn mtmt: DjVu,HAM, ICER, JPEG,

JBIG2, PGF,Wavelet compression

Kch

thc

nhnhphn

nhxm

nhmu

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nhdngnhqut:

JPEG/JFIF, Exif,TIFF, RAW, PNG,

GIF, BMP, PPM,PGM, PBM, PNM

nhvector: CGM,SVG, vvv

nh3D: PNS, JPS,MPO

Kiunn

Nn khng mtmt:ABO, GIF, JBIG, ,

PGF, PNG, TIFF

Nn mtmt: DjVu,HAM, ICER, JPEG,

JBIG2, PGF,Wavelet compression

Kch

thc

nhnhphn

nhxm

nhmu

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nhdngnhqut:

JPEG/JFIF, Exif,TIFF, RAW, PNG,

GIF, BMP, PPM,PGM, PBM, PNM

nhvector: CGM,SVG, vvv

nh3D: PNS, JPS,MPO

Kiunn

Nn khng mtmt:ABO, GIF, JBIG, ,

PGF, PNG, TIFF

Nn mtmt: DjVu,HAM, ICER, JPEG,

JBIG2, PGF,Wavelet compression

Kch

thc

nhnhphn

nhxm

nhmu

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nhdngnhqut:

JPEG/JFIF, Exif,TIFF, RAW, PNG,

GIF, BMP, PPM,PGM, PBM, PNM

nhvector: CGM,SVG, vvv

nh3D: PNS, JPS,MPO

Kiunn

Nn khng mtmt:ABO, GIF, JBIG, ,

PGF, PNG, TIFF

Nn mtmt: DjVu,HAM, ICER, JPEG,

JBIG2, PGF,Wavelet compression

Kch

thc

nhnhphn

nhxm

nhmu

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Phng to

Thu nh

Xoay

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Xn nh Mosaic

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BMP

JPEG

PNGGIF

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PSNR = 26.54 PSNR = 21.94 PSNR = 21.62

2

0 0

1( , ) ( , )

M N

i i

MSE I i j I i j MN

2

10

25510logPSNR

MSE

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0 0

1( , ) ( , )

255

M N

i j

MAE W i j W i j M N

MAE = 0 MAE = 0.0074 MAE = 0.214

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M ha bit t quan trngnht

Datrn skhc bitcccppixel

Datrn histogram 1

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5 3 3 3 7

5 5 3 3 3

4 4 5 5 0

1 2 2 2 2

1 2 4 4 1

5 3 3

001

5 0101

3 0011

3 0011

0

0

1

0100

0010

0011

4 2 3 3 7

5 5 3 3 3

4 4 5 5 0

1 2 2 2 2

1 2 4 4 1

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1 bitPSNR = 51.14

2 bitPSNR = 44.14

3 bitPSNR = 37.90

4 bit

PSNR = 31.77

5 bit

PSNR = 25.72

6 bit

PSNR = 19.89

7 bit

PSNR = 13.99

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Bc4Hnh thnh tn hiustego

x'= l+ (h'+ 1) / 2 = 209

y'= lh'/ 2=198

Bc3Tnh gi trkhcbit(chunv m

rng)

h=xy =5

h' = 2h + b= 11

Bc2

Tnh gi trtrung bnh l= (x+y) / 2=203

Bc1

Chia cptrn tn hiucover (x,y) = (206, 201) vib= 1

(206, 201)

b= 1

(209, 198)

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Bc4Tn hiuwatermark b= LSB(h') = 1

Bc3Tnh gi trkhcbitmrng h =x'y' =11

Bc2Tnh gi trtrung bnh l= (x'+y') / 2=203

Bc1

Chia cptrn tn hiucover (x',y') = (209, 198)

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Bc6

Truy hitn hiucoverx= + (h+ 1) / 2= 206

y= h/ 2= 201

Bc5

Tnh gi trkhcbit h= h'/ 2= 5

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5 3 3 3 7

5 5 3 3 3

4 4 5 5 01 2 2 2 2

1 2 4 4 1

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5 3 3 3 7

5 5 3 3 3

4 4 5 5 0

1 2 2 2 2

1 2 4 4 1

6 3 3 3 7

6 6 3 3 3

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

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76

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101101

1 0 11 0 1

4 3 4

6 6 4 3 4

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

6 3 3 3 7

6 6 3 3 3

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

6 3 3 3 7

6 6 3 3 3

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

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6 4 3 4 7

6 6 4 3 4

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

1 0 11 0 1

5 3 3 3 7

5 5 3 3 3

4 4 5 5 0

1 2 2 2 2

1 2 4 4 1

6 4 3 4 7

6 6 4 3 4

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

= 3

6 4 3 4 7

6 6 4 3 4

5 5 6 6 0

1 2 2 2 2

1 2 5 5 1

= 6

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Phchinhchagc

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Cng thcchuynitkhng gianRGB sang HSV, YUV.

u/khuytimcatngthutton

Mcv hnh catngthutton

Khnngchngchutncng