Distortion Based Image Quality Index

Jingwei Guan and Wai-kuen ChamE-mail: {jwguan,wkcham}@ee.cuhk.edu.hk

The Chinese University of Hong Kong

DL-BIQI

SECTION 1: TASK INTRODUCTION

3

Sub: DMOS = 0 DMOS = 47.2859 DMOS = 83.5533

Image Quality Assessment

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of the images. Smaller value better quality.

Different images have different visual quality scores.

4

Sub: DMOS = 0 DMOS = 47.2859 DMOS = 83.5533

Obj: Q = 3.57 Q = 45.6398 Q = 86.3695

Image Quality Assessment

Difference = |DMOS – Q|

Smaller difference more accurate IQA metric

Different images have different visual quality scores.

5

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

Images can be distorted by different type.

6

Images can be distorted by different type.

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

DMOS = 0 DMOS = 55.7986 DMOS = 83.2695

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of the images. Smaller value better quality.

7

DMOS = 0 DMOS = 47.2859 DMOS = 83.5533

Images can be distorted by different type.

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of the images. Smaller value better quality.

8

DMOS = 0 DMOS = 41.2840 DMOS = 58.7538

Images can be distorted by different type.

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of the images. Smaller value better quality.

9

DMOS = 0 DMOS = 51.4067 DMOS = 94.4101

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of reference image and distorted images. Smaller value better quality.

Images can be distorted by different type.

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

10

DMOS = 0 DMOS = 48.7926 DMOS = 65.4952

Notes:DMOS represents the Difference of Mean Opinion Scores(DMOS) of reference image and distorted images. Smaller value better quality.

Images can be distorted by different type.

Appearance of these images are different.

1. Gaussian Blur 2. JPEG 3. JPEG2000 4. White Noise 5. Fast Fading

SECTION 2: RELATED WORK & MOTIVATION

History of IQA Development

Full-reference (FR) Reduced-reference (RR) No-reference (NR)

Distortion Specific Non-distortion Specific

OUR TASK: No-reference non-distortion specific models

No-reference non-distortion specific models

Blind image quality index (BIQI)Probability summation model to combine the visual quality estimated for several distortion types together.

The probabilities:Hand-crafted features + support vector machine (SVM)

Distortion-specific visual quality scoresHand-crafted features +support vector regression (SVR)

[1] A.K. Moorthy and A. C. Bovik,“A two-step framework for constructing blind image quality indices,” Signal Processing Letters, IEEE, vol. 17, no. 5, pp. 513–516, 2010.

[1]

SECTION 3: PROPOSED DL-BIQI METHOD

Deep Learning based Blind Image Quality Index

Follow the probability summation model

The probabilities:Distortion type classification model ( ) Distortion-specific visual quality scoresN Distortion-specific quality estimation models ( )

DL-BIQI

DL-BIQI

SECTION 4: EXPERIMENTS

Distortion type classification

(a)

(b)

(c)

(d)

Distortion Type classification accuracy:

93.7%

Visual quality estimation

Visual quality estimation

Visual quality estimation

Thank you