Table 2 The NCD comparison of the conventional and proposed methods on the 24 test images in Figure 7(a).

[7]

[13]

[14]

[20]

[21]

[22]

[23]

[25]

Proposed

3.372

2.724

1.994

3.286

2.663

2.924

2.789

2.517

2.426

2.311

2.244

1.905

2.201

2.177

2.133

2.179

1.910

1.906

1.409

1.321

1.211

1.428

1.311

1.318

1.333

1.231

1.212

1.876

1.800

1.725

2.051

1.897

1.950

1.924

1.777

1.764

4.217

3.491

3.040

4.105

3.608

3.821

3.843

3.329

3.152

2.373

1.939

1.384

2.206

1.636

1.751

1.782

1.636

1.565

1.677

1.553

1.458

1.554

1.563

1.535

1.569

1.431

1.347

4.064

3.158

2.246

3.271

2.780

3.004

2.847

2.567

2.364

1.352

1.183

1.028

1.271

1.144

1.175

1.158

1.131

1.066

1.342

1.203

1.124

1.369

1.238

1.282

1.279

1.223

1.168

3.014

2.526

2.056

2.798

2.403

2.499

2.528

2.227

2.142

1.006

0.887

0.744

0.958

0.830

0.857

0.865

0.810

0.784

4.737

3.898

3.313

5.648

4.387

4.991

4.707

4.208

4.032

3.203

2.918

2.593

3.160

2.969

3.034

2.972

2.647

2.595

2.148

2.052

1.958

2.329

2.155

2.201

2.183

2.018

1.980

2.150

1.749

1.218

1.918

1.409

1.507

1.525

1.499

1.386

2.663

2.363

2.207

2.771

2.490

2.631

2.578

2.465

2.333

4.152

3.828

3.720

4.711

4.284

4.440

4.397

4.019

3.833

2.528

2.126

1.661

2.321

2.011

2.135

2.065

1.897

1.792

1.483

1.303

1.155

1.522

1.356

1.443

1.411

1.264

1.216

2.393

1.989

1.684

2.511

2.078

2.292

2.212

1.965

1.891

2.133

2.007

1.884

2.289

2.125

2.167

2.197

1.983

1.909

1.261

1.245

1.216

1.290

1.307

1.284

1.286

1.248

1.187

2.514

2.239

1.968

2.684

2.310

2.472

2.430

2.199

2.114

2.474

2.156

1.854

2.486

2.172

2.285

2.253

2.050

1.965