Author Affiliations
1Microelectronics Research and Development Center, Shanghai University, Shanghai 200072, China2School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200072, Chinashow less
Fig. 1. Luminance masking test image
Fig. 2. Contrast masking test image
Fig. 3. Results of visual experiment. (a) JND-luminance; (b) JND-eccentricity; (c) JND-contrast; (d) JND-block size
Fig. 4. Relationship among JND and different parameters. (a) Relationship among JND, luminance and eccentricity; (b) relationship among JND, luminance and contrast; (c) relationship among JND, block size and eccentricity
Fig. 5. CB-FJND model noise injection. (a) Original image; (b) noise injection with 3 pixel×3 pixel block; (c) noise injection with 5 pixel×5 pixel block; (d) noise injection with 7 pixel×7 pixel block; (e) result of Ref. [
7] model; (f) results of Ref. [
9] model
Fig. 6. Lena bit-plane images. (a) 23 bit-planes; (b) 25 bit-planes
Fig. 7. Distribution of bit16 before and after modification of
Fig. 8. Comparison of compression effect and partially enlarged image. (a) Algorithm in Ref. [
10]; (b) cruciate block compression algorithm (19 subfields); (c) cruciate block compression algorithm (25 subfields)
Fig. 9. Hardware implementation system block diagram
Fig. 10. Picture of FPGA test platform
Fig. 11. Image compression effect and detail enlargement comparison of Lena. (a) Algorithm in Ref. [
10]; (b) our algorithm (19 subfields); (c) our algorithm (25 subfields)
Attribute | Luminance masking test | Contrast masking test |
---|
Eccentricity /(°) | 1,2,3,5,10,15,20,25,30,35,40,45,50 | 1,2,3,5,10,15,20,25,30,35,40,45,50 | Luminance | 0,10,20,40,60,80,100,125,150,180,200,220,240 | 60,100,150,180,220 | Contrast | 0 | 0,20,40,60,80 |
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Table 1. Luminance/contrast masking test variable control
Attribute | Value |
---|
Block size /pixel | 2,3,5,7,10 | Luminance | 0,10,20,40,60,80,100,125,150,180,200,220,240 | Eccentricity /(°) | 1,2,3,5,10,15,20,25,30,35,40,45,50 |
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Table 2. Block masking test variable control
Stage | Maximum run length | Average rate of variability /% |
---|
Before modification | 49 | 37.86 | After modification | 61 | 29.88 |
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Table 3. Comparison of bit16 before and after threshold modification
Subfield number | Weight distribution |
---|
19 | 16{15} 8 4 2 1 | 20 | 16{15} 8 4 1{3} | 21 | 16{15} 8 2{2} 1{3} | 22 | 16{15} 8 2 1{5} | 23 | 16{15} 8 1{7} | 24 | 16{15} 4{2} 1{7} | 25 | 16{15} 4 2{2} 1{7} |
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Table 4. 19‒25 bit-plane weights
Subfield number | Fractional subfield weights |
---|
20 | 8∶4∶1∶1∶1 | 8∶2∶2∶2∶1 | 4∶4∶4∶2∶1 | 21 | 8∶2∶2∶1∶1∶1 | 4∶4∶4∶1∶1∶1 | 4∶4∶2∶2∶2∶1 | 22 | 8∶2∶1∶1∶1∶1∶1 | 4∶4∶2∶2∶1∶1∶1 | 4∶2∶2∶2∶2∶2∶1 | 23 | 8∶1∶1∶1∶1∶1∶1∶1 | 4∶4∶2∶1∶1∶1∶1∶1 | 4∶2∶2∶2∶2∶1∶1∶1 | 2∶2∶2∶2∶2∶2∶2∶1 | 24 | 4∶4∶1∶1∶1∶1∶1∶1∶1 | 4∶2∶2∶2∶1∶1∶1∶1∶1 | 2∶2∶2∶2∶2∶2∶1∶1∶1 | 25 | 4∶2∶2∶1∶1∶1∶1∶1∶1∶1 | 2∶2∶2∶2∶2∶1∶1∶1∶1∶1 |
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Table 5. Fractional subfield weight division strategy
Subfield number | Fractional subfield weights | PSNR /dB | SSIM |
---|
Lena | Peppers | Baboon | Lena | Peppers | Baboon |
---|
20 | 8∶4∶1∶1∶1 | 43.2422 | 42.7886 | 41.8702 | 0.9988 | 0.9987 | 0.9968 | 8∶2∶2∶2∶1 | 41.1474 | 40.4945 | 38.9426 | 0.9979 | 0.9980 | 0.9959 | 4∶4∶4∶2∶1 | 38.0684 | 37.6907 | 37.7089 | 0.9959 | 0.9964 | 0.9922 | 21 | 8∶2∶2∶1∶1∶1 | 41.1474 | 40.4945 | 38.9426 | 0.9979 | 0.9980 | 0.9959 | 4∶4∶4∶1∶1∶1 | 38.2299 | 37.9056 | 37.7089 | 0.9961 | 0.9966 | 0.9922 | 4∶4∶2∶2∶2∶1 | 38.1131 | 37.7037 | 37.7089 | 0.9959 | 0.9965 | 0.9922 | 22 | 8∶2∶1∶1∶1∶1∶1 | 40.5129 | 39.9217 | 38.9426 | 0.9977 | 0.9976 | 0.9959 | 4∶4∶2∶2∶1∶1∶1 | 38.1131 | 37.7037 | 37.7089 | 0.9959 | 0.9965 | 0.9922 | 4∶2∶2∶2∶2∶2∶1 | 35.4802 | 36.2174 | 34.9804 | 0.9920 | 0.9949 | 0.9907 | 23 | 8∶1∶1∶1∶1∶1∶1∶1 | 38.7953 | 38.3462 | 37.7445 | 0.9967 | 0.9962 | 0.9953 | 4∶4∶2∶1∶1∶1∶1∶1 | 37.8025 | 37.6806 | 37.7089 | 0.9956 | 0.9965 | 0.9922 | 4∶2∶2∶2∶2∶1∶1∶1 | 35.4802 | 36.2174 | 34.9804 | 0.9920 | 0.9949 | 0.9907 | 2∶2∶2∶2∶2∶2∶2∶1 | 32.4729 | 32.7110 | 34.3232 | 0.9834 | 0.9909 | 0.9864 | 24 | 4∶4∶1∶1∶1∶1∶1∶1∶1 | 37.7469 | 37.8498 | 37.7089 | 0.9955 | 0.9966 | 0.9922 | 4∶2∶2∶2∶1∶1∶1∶1∶1 | 35.4802 | 36.2174 | 34.9804 | 0.9920 | 0.9949 | 0.9907 | 2∶2∶2∶2∶2∶2∶1∶1∶1 | 32.4729 | 32.7110 | 34.3232 | 0.9834 | 0.9909 | 0.9864 | 25 | 4∶2∶2∶1∶1∶1∶1∶1∶1∶1 | 35.4802 | 36.2174 | 34.9804 | 0.9920 | 0.9949 | 0.9907 | 2∶2∶2∶2∶2∶1∶1∶1∶1∶1 | 32.4729 | 32.7110 | 34.3232 | 0.9834 | 0.9909 | 0.9864 | JPEG quality 100 | 37.4874 | 32.8036 | 29.2941 | 0.9946 | 0.9886 | 0.9511 | JPEG quality 90 | 34.7660 | 31.3296 | 27.9459 | 0.9902 | 0.9826 | 0.9333 | JPEG quality 80 | 33.6061 | 30.5420 | 26.6553 | 0.9875 | 0.9789 | 0.9143 |
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Table 6. Image quality after compression with different weight distribution bit-planes
Image | Ref. [10] | Ref. [11] | CB-FJND with different subfield numbers |
---|
19 | 20 | 21 | 22 | 23 | 24 | 25 |
---|
Lena | 36.00 | 53.47 | 36.57 | 32.96 | 31.51 | 30.26 | 28.71 | 27.82 | 26.10 | Peppers | 40.20 | 56.22 | 40.18 | 36.42 | 34.81 | 33.39 | 31.74 | 30.94 | 29.10 | Baboon | 51.03 | 63.68 | 50.43 | 47.67 | 45.06 | 43.15 | 41.31 | 39.91 | 36.84 | Average | 42.41 | 57.79 | 42.39 | 39.02 | 37.13 | 35.6 | 33.92 | 32.89 | 30.68 |
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Table 7. Bit compression rate of compressed image
Image | Ref. [10] | Ref. [11] | CB-FJND with different subfield numbers |
---|
19 | 20 | 21 | 22 | 23 | 24 | 25 |
---|
Lena | 38.92 | 37.73 | 43.63 | 43.24 | 41.15 | 40.52 | 38.80 | 37.75 | 35.48 | Peppers | 39.85 | 38.16 | 43.44 | 42.79 | 40.50 | 39.92 | 38.35 | 37.85 | 36.21 | Baboon | 37.44 | 36.91 | 42.81 | 41.87 | 38.95 | 38.95 | 37.75 | 37.71 | 34.98 | Average | 38.73 | 37.60 | 43.29 | 42.63 | 40.20 | 39.80 | 38.30 | 37.77 | 35.56 |
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Table 8. PSNR of compressed image
Image | Ref. [10] | Ref. [11] | CB-FJND with different subfield numbers |
---|
19 | 20 | 21 | 22 | 23 | 24 | 25 |
---|
Lena | 0.9974 | 0.9813 | 0.9989 | 0.9988 | 0.9979 | 0.9977 | 0.9967 | 0.9955 | 0.9920 | Peppers | 0.9973 | 0.9807 | 0.9988 | 0.9987 | 0.9980 | 0.9976 | 0.9962 | 0.9966 | 0.9949 | Baboon | 0.9955 | 0.9792 | 0.9975 | 0.9968 | 0.9959 | 0.9959 | 0.9953 | 0.9922 | 0.9907 | Average | 0.9967 | 0.9804 | 0.9984 | 0.9981 | 0.9973 | 0.9971 | 0.9961 | 0.9948 | 0.9925 |
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Table 9. SSIM of compressed image