答题卡识别

识别标准答题卡中的选择题、判断题，根据指定的识别区域识别填涂的选项，转换成答案如A、B、C、D
如需要识别考生编号，也可以设计含有考生编号填涂的答题卡，识别答案的同时识别考生编号，直接计算对应考生的成绩
示例答题卡图片

{"area":[
            {"name":"t1","opts":[
                {"name":"A","x":78,"y":656,"width":40,"height":34},
                {"name":"B","x":353,"y":659,"width":40,"height":34},
                {"name":"C","x":627,"y":658,"width":40,"height":34}
            ]},{"name":"t2","opts":[
                {"name":"A","x":78,"y":775,"width":40,"height":34},
                {"name":"B","x":353,"y":775,"width":40,"height":34},
                {"name":"C","x":627,"y":775,"width":40,"height":34}
            ]},
            {"name":"n1","x":67,"y":200,"width":190,"height":34,"optNo":4},
            {"name":"n2","x":67,"y":234,"width":190,"height":34,"optNo":4},
            {"name":"n3","x":67,"y":268,"width":190,"height":34,"optNo":4},
            {"name":"n4","x":67,"y":302,"width":190,"height":34,"optNo":4},
            {"name":"n5","x":67,"y":336,"width":190,"height":34,"optNo":4},
            {"name":"n6","x":345,"y":200,"width":190,"height":34,"optNo":4},
            {"name":"n7","x":345,"y":234,"width":190,"height":34,"optNo":4},
            {"name":"n8","x":345,"y":268,"width":190,"height":34,"optNo":4},
            {"name":"n9","x":345,"y":302,"width":190,"height":34,"optNo":4},
            {"name":"n10","x":345,"y":336,"width":190,"height":34,"optNo":4},
            {"name":"n11","x":623,"y":200,"width":190,"height":34,"optNo":4},
            {"name":"n12","x":623,"y":234,"width":190,"height":34,"optNo":4},
            {"name":"n13","x":623,"y":268,"width":190,"height":34,"optNo":4},
            {"name":"n14","x":623,"y":302,"width":190,"height":34,"optNo":4},
            {"name":"n15","x":623,"y":336,"width":190,"height":34,"optNo":4},
            {"name":"n16","x":901,"y":200,"width":190,"height":34,"optNo":4},
            {"name":"n17","x":901,"y":234,"width":190,"height":34,"optNo":4},
            {"name":"n18","x":901,"y":268,"width":190,"height":34,"optNo":4},
            {"name":"n19","x":901,"y":302,"width":190,"height":34,"optNo":4},
            {"name":"n20","x":901,"y":336,"width":190,"height":34,"optNo":4},
            {"name":"n21","x":67,"y":400,"width":190,"height":34,"optNo":4},
            {"name":"n22","x":67,"y":434,"width":190,"height":34,"optNo":4},
            {"name":"n23","x":345,"y":400,"width":190,"height":34,"optNo":4},
            {"name":"n24","x":345,"y":434,"width":190,"height":34,"optNo":4},
            {"name":"n25","x":623,"y":400,"width":190,"height":34,"optNo":4},
            {"name":"n26","x":623,"y":400,"width":190,"height":34,"optNo":4,"opt":["甲","乙","丙","丁"]}
 ]
}