International Core Journal of Engineering 2020-26 | Page 86

澳 model using 320 real images. The relevant experimental results are shown in Table II. for model training. (3) SynImg-32Cls+RealImg: Pre-train the model using 3 200 synthetic images, then fine-tune the T ABLE II R ESULTS OF THE SYNTHESIS ALGORITHM AND COMPARISON WITH [12]. Method Setting: Adidas Aldi Apple Becks BMW Carls Chim Training/Test Corona DHL Erdi Esso Fedex Ferra Ford Fost Image Split Google Guin Hein HP Milka Nvid Paul Pepsi (per logo class) RealImg([12]) SynImg-32Cls([12]) SynImg-32Cls + RealImg᷉[12]᷊ RealImg (This paper) SynImg-32Cls᷉This paper᷊ Coke Ritt Shell Sing Starb Stel Texa Tsin Ups 23.7 57.5 63.0 69.6 63.7 50.6 55.2 26.8 Training: 10 RealImg 79.0 25.8 61.2 44.2 45.9 80.6 64.3 43.2 Test: 60 RealImg 47.7 58.2 61.8 21.3 19.4 17.4 48.2 17.8 34.8 45.8 71.8 70.2 79.6 56.7 56.9 52.2 9.4 47.3 9.6 70.3 39.9 28.3 15.8 21.7 Training: 100 SynImg 6.1 11.1 4.1 44.7 22.9 60.9 43.6 28.8 Test: 60 RealImg 23.0 16.7 43.1 9.9 4.6 1.1 39.1 9.7 22.7 38.3 15.5 65.6 28.7 55.1 27.4 20.1 26.8 63.7 65.8 72.7 81.3 52.7 63.6 30.0 Training: 100 SynImg 76.0 31.5 63.0 52.2 54.3 90.0 84.0 46.6 +10 RealImg 58.0 52.6 65.2 23.2 24.0 12.5 54.1 23.6 Test: 60 RealImg 37.9 45.6 75.0 73.8 79.0 64.2 57.4 54.4 24.4 57.2 66.6 72.0 70.8 42.8 55.3 24.8 Training: 10 RealImg 82.8 29.5 62.5 44.1 42.7 87.2 59.3 39.9 Test: 60 RealImg 51.2 54.6 65.1 24.2 15.5 16.9 52.3 17.4 32.3 44.7 72.7 69.7 77.3 62.5 52.6 44.3 38.6 54.0 34.6 44.1 17.6 18.4 33.9 20.6 Training: 100 SynImg 8.2 21.5 12.1 49.6 16.6 28.2 35.4 50.3 Test: 60 RealImg 46.4 40.0 33.1 26.1 9.9 18.8 64.5 22.3 39.4 45.5 15.8 55.5 17.6 47.5 38.7 39.9 51.1 62.1 29.8 31.0 69.0 74.3 78.0 76.6 Training: 100 SynImg 88.5 35.3 70.9 53.5 49.0 87.9 76.9 52.9 +10 RealImg 61.7 66.9 69.3 34.1 25.8 26.2 67.8 22.8 Test: 60 RealImg 41.8 45.5 79.4 72.5 79.7 69.2 62.1 61.5 36.2 61.3 30.1 46.9 25.3 30.8 32.2 22.3 Training: 100 SynImg 11.4 16.7 19.6 47.1 28.0 33.2 33.8 50.1 RealImg᷉fusion᷊ +10 RealImg 45.7 41.6 37.1 25.6 13.0 16.3 63.7 20.9 ᷉This paper᷊ Test: 60 RealImg 33.4 45.0 14.1 62.7 22.8 46.4 43.5 36.6 Training: 100 SynImg 31.1 71.2 71.6 71.7 84.4 48.0 66.3 28.5 RealImg᷉fusion᷊ +10 RealImg 84.4 33.3 82.0 51.7 51.0 90.3 76.4 54.8 +RealImg ᷉This paper᷊ Fine-tune˖10 RealImg 59.6 67.8 69.4 37.8 23.2 22.9 66.0 23.6 Test: 60 RealImg 40.6 46.0 75.3 77.2 83.5 67.8 63.6 64.2 SynImg-32Cls + RealImg (This paper) SynImg-32Cls + SynImg-32Cls + mAP 50.4 27.6 54.8 50.5 32.6 58.5 34.2 58.9 which fully verifies the effectiveness of the synthesis algorithm. It is worth mentioning that the improvement in performance is not dependent on additional manual labeling, nor does it require the construction of a large (463 categories) common set of logo exemplars as in [12]. In Table II, simply using 320 real images for training, RealImg (This paper) obtained similar experimental results to RealImg ([12]) (50.5% VS. 50.4%), although 50.5% is a result of one experiment, actually for RealImg this paper has carried out several experiments, and the mAP is changed very little at around 50.0%. The reason why the experimental results are unstable is mainly due to the randomness of the neural network algorithm itself (such as the optimization algorithm of Faster R-CNN using random gradient descent). Therefore, this paper basically reproduces the experimental results of [12] on FlickrLogos-32. On this basis, SynImg-32Cls(This paper) and SynImg-32Cls+RealImg(This paper) using the proposed synthesis algorithm have obvious advantages compared with the method of [12] (32.6% VS. 27.6%, 58.5% VS. 54.8%), In addition, this paper has also observed that although SynImg-32Cls(This paper) is greatly improved compared to SynImg-32Cls ([12]), the effect of using only synthetic images for training is still far from the method of using a small number of real images. The potential cause of this situation may be that there is a large distribution difference between the real image and the synthetic image, and the details learned by the model on the synthetic image are difficult to generalize into the real image. From this point of view, the key to the synthetic data extension training set 64