xzbautomarkapi/utils/ansDetect.py

#-*-coding:utf-8 -*-
##############################
#python使用ocr完成精确模板匹配
##############################

import cv2
import os
import pytesseract
from pytesseract import Output
from PIL import Image
import numpy as np
import pprint
from functools import reduce
import math
from utils.bdocr import rec_general_num


def calc_overlap(rec1,rec2):
    """
    """
    if rec1 and rec2:
        x1,y1,w1,h1 = rec1["x"],rec1["y"],rec1["w"],rec1["h"]
        x2,y2,w2,h2 = rec2["x"],rec2["y"],rec2["w"],rec2["h"]
        #重叠区域
        startx = min(x1,x2)
        endx = max(x1+w1,x2+w2)
        width = w1+w2-(endx-startx)
        stary = min(y1,y2)
        endy = max(y1+h1,y2+h2)
        height = h1+h2-(endy-stary)
        if width <= 0 or height <= 0:
            return 0.0
        else:
            area = width * height
            area1 = w1*h1
            area2 = w2*h2
            ratio = float(area)/(area1+area2-area)
            return ratio
    return 0.0


def crop_img_local(orgimg,new_img,point=()):
    """
    切割图片
    """
    img = Image.open(orgimg)
    region = img.crop(point)
    region.save(new_img, format="png")

    return new_img

def write_img(imgpath,data):
    """
    """
    img = cv2.imread(imgpath)
    for item in data:
        x = item["x"]
        y = item["y"]
        w = item["w"]
        h = item["h"]

        pt = (item["x"],item["y"])
        right_bottom = (x + w, y + h)

        cv2.rectangle(img, pt, right_bottom, (0, 0, 255), 2)

    cv2.imwrite("/tmp/templateDetectResult.png",img)


def recText(imgpath,choices):
    """
    识别出ABCD选项并分隔出模板图像
    """
    img = cv2.imread(imgpath)

    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    cv2.imwrite("/tmp/src_gray.png",gray)

    _,thresh = cv2.threshold(gray,0,250,cv2.THRESH_BINARY_INV | cv2.THRESH_OTSU)
    cv2.imwrite("/tmp/src_thresh.png",thresh)

    hImg,wImg,_ = img.shape

    boxes = pytesseract.image_to_boxes(img)
    for b in boxes.splitlines():
        b = b.split(" ")
        for ans in choices:
            if b[0] == ans:
                x1,y1,x2,y2 = int(b[1]),int(b[2]),int(b[3]),int(b[4])
                w = x2-x1
                h = y2-y1
                #cv2.rectangle(img,(x1-w,hImg-y1+2),(x2+w,hImg-y2-2),(0,0,255),2)
                crop_point = (x1-w-2,hImg-y1-(h+4),x2+w+2,hImg-y2+h+4)
                crop_img_local(imgpath,"/tmp/{}.png".format(ans),crop_point)
                break
    cv2.imwrite("/tmp/ocrResult.png",img)


def round_int(x):
    """整数个位四舍五入
    """
    if x%100%10 < 8:
        return int(x/10)*10
    else:
        return (int(x/10)+1)*10

def recTemplate(src,choices):
    """模板匹配
    """
    data = []
    img = cv2.imread(src)
    
    for ans in choices:
        tplpath = "/tmp/{}.png".format(ans)
        template = cv2.imread(tplpath, 0)
        h, w = template.shape[:2]

        img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        res = cv2.matchTemplate(img_gray, template, cv2.TM_CCOEFF_NORMED)

        threshold = 0.8
        loc = np.where(res >= threshold)
        for pt in zip(*loc[::-1]):
            x,y = int(pt[0]),int(pt[1])
            z = math.sqrt(x**2+y**2)

            data.append({"x":x,"y":y,"w":w,"h":h,"z":z})

    return data


def format_data(data):
    """通过xy相对位置分组
    """
    groups = []
    data = sorted(data,key=lambda x:x["x"])
    #pprint.pprint(data)

    max_x = data[0]["x"]
    group = [] 
    for i,item in enumerate(data):
        cur_w = item["w"]
        cur_x = item["x"]
        dis = cur_x - max_x
        if dis < cur_w*2:
            group.append(item)
        else:
            groups.append(group)
            group = [item]

        max_x = cur_x
    groups.append(group)
    #
    for i,item in enumerate(groups):
        groups[i] = list(sorted(item,key=lambda x:x["y"]))

    return groups


def remove_repeat(data):
    """相同位置的矩形去重
    """
    for i,item in enumerate(data):
        for j,jtem in enumerate(data):
            if i == j:
                continue
            else:
                ratio = calc_overlap(item,jtem)
                if ratio >0.5:
                    data[j] = None
    data = [x for x in data if x]
    return data


def rec_stand_ans_points(srcimg,choices):
    """
    通过模板匹配识别出每一个选项框的位置
    """
    recText(srcimg,choices)
    data = recTemplate(srcimg,choices)
    data = sorted(data,key=lambda x:x["x"])

    write_img(srcimg,data)

    #去重
    data = remove_repeat(data)

    #先分组
    data = format_data(data)

    return data


def get_std_xy(qnos,data,choices,order=1):
    """
    order:1/2,1竖排2横排
    获取每一道选择题的标准坐标
    """
    step = len(choices)
    newdata = []
    if order == 1:
        for item in data:
            choices = [item[i:i+step] for i in range(0,len(item),step)]
            newdata.extend(choices)

    pprint.pprint(newdata)
    #将分好组的数据分配到每一道题上面
    std_xy_data = {}
    for fpoints in newdata:
        fpoints = list(sorted(fpoints,key=lambda x:x["z"]))
        fpoint = fpoints[0]
        for k,v in qnos.items():
            top,left,width,height = v["top"],v["left"],v["width"],v["height"]
            if fpoint["y"] > top-height/2 and fpoint["y"] < top+height/2 and left < fpoint["x"] and fpoint["x"] < left + width:
                std_xy_data[k] = fpoints

    #newdata = list(sorted(newdata,key=lambda x:x["x"]))
    #std_xy_data = dict(zip(qnos,newdata))
    pprint.pprint(std_xy_data)
    return std_xy_data


def rec_std_ans(srcimg):
    """识别标准答题卡
    """
    qnos,qnos_dct,choices,rank_order = rec_general_num(srcimg)
    data = rec_stand_ans_points(srcimg,choices)
    std_xy_data = get_std_xy(qnos_dct,data,choices,rank_order)
    return std_xy_data


if __name__ == "__main__":
    srcimg = "/tmp/test6.png"
    srcimg = "/tmp/test_0_crop.png"
    std_ans_data = rec_std_ans(srcimg)
    pprint.pprint(std_ans_data)