Visual Evaluation of JPEG 2000 Color Image Compression

Performance (N1583)

Testing GroupTroy Chinen, Fujifilm Software California

Alan Chien, Eastman Kodak

April 10, 2023Tokyo

2

Testing Goals

• Quantitative– For a given set of JPEG 2000 bitrates, compute the

corresponding quality-equivalent JPEG bitrates for color images.

• Qualitative– Characterize JPEG 2000 color compression

artifacts.

April 10, 2023Tokyo

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Testing method

• Insert JPEG 2000 images between JPEG images of bounding quality.

• Record mean number of bytes for each insertion; fit to Gaussian distribution

11 22 33 44 55 66 77 88 99 1010

C(0.25bpp)

C(0.25bpp)

B(0.5bpp)

B(0.5bpp)

A(0.75bpp)

A(0.75bpp)

D(1.0bpp)

D(1.0bpp)

0.3bpp 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.4

Ordered JPEG images

Unordered JPEG 2000 images

VL

April 10, 2023Tokyo

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Testing Method (ctd)

• 6 scenes: bike, bottles, bride, harbor, woman, wool• 10 Reference JPEG images per scene

– default mode cjpeg, optimized Huffman tables

– 0.3 ~ 1.0 (0.1 increments), 1.2, 1.4bpp

• 4 JPEG 2000 images per scene– Default mode, VM5.2

– Fweights table T15PB

– 0.25, 0.50, 0.75, 1.0 bpp

April 10, 2023Tokyo

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Testing Method (ctd)

• Hardcopy: 300 dpi, 24 bit color• Blind testing• 6 Observers• VL (visually lossless) rankings were not included

in the summarizing statistics

April 10, 2023Tokyo

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Results: aggregate

0.5313

0.7762

0.9153

1.1282

0.25

0.50

0.75

1.00

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

1.4000

1.6000

0.00 0.20 0.40 0.60 0.80 1.00 1.20

JPEG 2000 bit rate

JPE

G b

it r

ate

36%

53%

18%

11%

Error bars = 2 sigma

April 10, 2023Tokyo

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Results: bike

0.47

0.68

0.90

1.16

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Results: bottles

0.50

0.86 0.84

1.01

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Results: bride

0.55

0.820.93

1.15

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Results: harbor

0.60

0.84

1.021.12

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Results: woman

0.52

0.65

0.88

1.14

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Results: wool

0.53

0.840.89

1.20

0.25

0.5

0.75

1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 0.2 0.4 0.6 0.8 1 1.2

JPEG 2000 bit rate

JPE

G b

it r

ate

April 10, 2023Tokyo

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Qualitative Results

• No color distortions observed

• Most JP2 images at 1.0bpp were VL (in print)

• Trends:

Bit Rate

Qua

lity

JPGSharpnessJPG Blocking

JP2 Sharpness

JP2 Blocking

April 10, 2023Tokyo

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Conclusions

• JPEG 2000 filesizes are smaller than JPEG by• 53% at 0.25bpp

• 36% at 0.5 bpp

• 18% at 0.75 bpp

• 11% at 1.0 bpp

• Distortion types of JPEG and JPEG 2000 are fundamentally different, nevertheless consistent rankings were observed.