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Abstract:
Layout analysis is the first step in automatic grading and other OCR tasks. Although various layout analysis technologies have been developed for different application scenarios, existing approaches still have difficulty in achieving high accuracy on answer sheet analysis. By combining the deep neural network object detection model YOLOv5s and traditional text extraction methods, a layout analysis method for answer sheets is proposed in this paper. The foreground and background of aligned answer sheets are separated by a method that we propose based on the variation in the pixel gradient. Then, a YOLOv5s-DC model is trained to detect the handwriting texts in the answer sheets, and MSER (Maximally Stable Extremal Regions) is applied to the answer sheets to extract the missing parts and background texts. The decoupled YOLO head replaces the original YOLO head for higher performance. Quality focal loss and efficient IoU loss are employed during loss calculation to supervise the classification and regression, respectively. After the detection, the seam carving algorithm and other rules are applied to the bounding boxes to improve the extraction results. The mean average precision of YOLOv5s-DC is 91.6%, which is 3.2% higher than that of YOLOv5s. The pixel accuracy of our text extraction method is 99.92%. The experimental results verify that our method can effectively and accurately analyze the layout of answer sheets.
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Source :
VISUAL COMPUTER
ISSN: 0178-2789
Year: 2023
Issue: 9
Volume: 40
Page: 6111-6122
3 . 5 0 0
JCR@2022
Cited Count:
WoS CC Cited Count: 1
SCOPUS Cited Count: 2
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 2
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