Halcon OCR字符识别（极坐标转换，字符识别）

HalconOCR字符识别实战

最新推荐文章于 2025-10-09 16:45:30 发布

原创最新推荐文章于 2025-10-09 16:45:30 发布 · 677 阅读

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Halcon OCR字符识别（极坐标转换，字符识别）

请添加图片描述

代码

* 1.加载图片 ***************************************************
dev_close_window ()
read_image (Image, './img')
get_image_size (Image, Width, Height)
dev_get_window (WindowHandle)
dev_set_colored (12)
dev_set_draw ('margin')
dev_display (Image)

* 2.获取字符区域 ***************************************************
rgb1_to_gray (Image, GrayImage)
get_image_size (GrayImage, Width, Height)
threshold (GrayImage, Region, 40, 140)
connection (Region, ConnectedRegions)
select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 13000, 99999)
fill_up (SelectedRegions, RegionFillUp)
opening_circle (RegionFillUp, RegionOpening, 5.5)

* 3.字符环形区域 ***************************************************
gen_contour_region_xld (RegionOpening, Contours, 'border')
segment_contours_xld (Contours, ContoursSplit, 'lines_circles', 5, 4, 2)
length_xld (ContoursSplit, Lengths)
LengthIndex := sort_index(Lengths)[|Lengths| - 1]
select_obj(ContoursSplit, ObjectSelected, LengthIndex + 1)

fit_circle_contour_xld (ObjectSelected, 'algebraic', -1, 0, 0, 3, 2, Row, Column, Radius, StartPhi, EndPhi, PointOrder)
gen_circle (Circle, Row, Column, Radius)

dilation_circle (Circle, RegionDilation, 5.0)
erosion_circle (Circle, RegionErosion, 30)

difference (RegionDilation, RegionErosion, RegionDifference)
reduce_domain (GrayImage, RegionDifference, ImageReduced)
stop()

* 4.极坐标转换与旋转 ***************************************************
polar_trans_image_ext (ImageReduced, PolarTransImage, Row, Column, \
                       rad(85), rad(280), Radius-100, Radius, \
                       750, 250, 'nearest_neighbor')
rotate_image (PolarTransImage, ImageRotate, 90, 'constant')


* 5.获取文本区域 ***************************************************
threshold (ImageRotate, RegionText, 160, 255)
threshold (ImageRotate, RegionBack, 35, 80)
fill_up (RegionBack, RegionBack)
connection (RegionBack, ConnectedRegions1)
select_shape_std (ConnectedRegions1, SelectedBack, 'max_area', 70)

intersection (RegionText, SelectedBack, RegionIntersection)
connection (RegionIntersection, ConnectedRegions2)
select_shape (ConnectedRegions2, SelectedTexts, 'area', 'and', 10, 99999)

* 6. 获取文本外接矩形***************************************************
opening_circle (SelectedTexts, SelectedTexts, 1.5)
union1 (SelectedTexts, RegionUnion)

closing_rectangle1 (RegionUnion, RegionClosing, 80, 3)
fill_up (RegionClosing, RegionFillUp1)
connection (RegionFillUp1, ConnectedRegions3)
shape_trans (ConnectedRegions3, RegionTrans, 'rectangle1')
dilation_rectangle1 (RegionTrans, RegionDilation1, 15, 5)
sort_region (RegionDilation1, SortedRegions, 'first_point', 'true', 'row')

invert_image (ImageRotate, ImageInvert)

* 7.循环识别字符 ***************************************************
* 读取OCR
read_ocr_class_mlp ('Industrial_0-9A-Z_NoRej.omc', OCRHandle)

* 存放结果字典
create_dict (DictHandle)

count_obj (SortedRegions, Number)
for Index := 1 to Number by 1
    * 获取区域内文本
    select_obj (SortedRegions, SubRect, Index)
    intersection (SubRect, SelectedTexts, SubRegion)
    
    connection (SubRegion, ConnectedRegions4)
    sort_region (ConnectedRegions4, SortedRegions1, 'first_point', 'true', 'column')
    * 字符识别
    do_ocr_multi_class_mlp (SortedRegions1, ImageInvert, OCRHandle, Class, Confidence)
    
    area_center (SubRect, Area, RowRect, ColumnRect)
    tuple_mean (Confidence, MeanConfidence)
    * 拼接结果
    Concat := ''
    if(|Class| == 1)
        Concat := Class
    else
        for Index1 := 1 to |Class|by 1
            Concat := Concat + Class[Index1-1] 
        endfor
    endif
    * 结果写入字典
    set_dict_tuple (DictHandle, Index, [RowRect, ColumnRect, Concat, MeanConfidence])
    
endfor


* 8.显示结果 ***************************************************
dev_clear_window ()
dev_display (ImageRotate)
set_display_font (WindowHandle, 16, 'mono', 'true', 'false')
* 循环解析字典
get_dict_param (DictHandle, 'keys', [], AllKeys)
for Index := 0 to |AllKeys| - 1 by 1
    
  NextKey := AllKeys[Index]
  * 获取数据
  get_dict_param (DictHandle, 'key_data_type', NextKey, NextKeyDataType)
  get_dict_tuple (DictHandle, NextKey, ResultTuple)
  
  * 显示区域
  RowText := ResultTuple[0] - 15
  CloumnText := ResultTuple[1] + 20
  * 显示结果
  result_msg := ResultTuple[2] + ' ' +   ResultTuple[3] $ '.3f'
  disp_message (WindowHandle, result_msg, 'image', RowText, CloumnText, 'blue', 'true')

endfor