边缘缺陷检测

* This program shows how to calculate the pointwise
* distance of two contours to inspect the camera frame
* of a phone housing.
* 
* It uses the operator distance_contours_xld to calculate
* the distance between the inner and outer contour of the
* frame and the operator segment_contour_attrib_xld
* to extract the defects for visualization.
* 
* Set the thresholds for the allowed distances in pixels
MinWidth := 30
MaxWidth := 35
SmoothnessTolerance := .2
* 
* Initialize visualization
dev_update_off ()
dev_close_window ()
read_image (Image, 'plastic_parts/phone_camera_frame_01')
dev_open_window_fit_image (Image, 0, 0, -1, -1, WindowHandle)
set_display_font (WindowHandle, 14, 'mono', 'true', 'false')
Colors := ['white','green','yellow','orange','red']
Legend[0] := 'Legend:'
Legend[1] := 'Extracted contours'
Legend[2] := 'Frame too narrow'
Legend[3] := 'Frame too wide'
Legend[4] := 'Contour defect'
* 
* Main loop:
* Inspect the camera frame
* 
NumImages := 2
for I := 1 to NumImages by 1
    read_image (Image, 'plastic_parts/phone_camera_frame_' + I$'02')
    * 
    * Extract frame edges
    * 
    * Select the frame region
    threshold (Image, Region, 100, 255)
    dilation_rectangle1 (Region, RegionDilation, 15, 15)
    reduce_domain (Image, RegionDilation, ImageReduced)
    * Extract edges in the reduced image domain
    edges_sub_pix (ImageReduced, Edges, 'canny', 0.7, 10, 60)
    union_adjacent_contours_xld (Edges, UnionContours, 7, 7, 'attr_keep')
    select_shape_xld (UnionContours, SelectedContours, 'contlength', 'and', 700, 99999)
    count_obj (SelectedContours, Number)
    * Select the inner and the outer contour
    *获取轮廓的长度
    length_xld (SelectedContours, Length)
    
    *tuple_sort_index按升序对元组的所有元素进行排序，并按元素值从小到大的顺序返回相应元素在原来的元祖中的索引，元素值最小的索引为0，
   
    tuple_sort_index (Length, Indices)
    
    *选择最里面的轮廓,selected_obj的Index是从1开始的，素组的索引是从0开始的，所以需要加1
    *Indices[1] = 0，轮廓长度最小，Index是从1开始的，所以Indices[1]得加1
    select_obj (SelectedContours, InnerContour, Indices[1]+1 )
    *选择最外面的轮廓
    select_obj (SelectedContours, OuterContour, Indices[3]+1 )
    * 先计算两个轮廓之间的距离
    * Calculate the distances between the inner and outer contour.
    * The distances are stored as an attribute to the output contour.
    distance_contours_xld (InnerContour, OuterContour, OuterContourWithWidth, 'point_to_segment')
    * Get the contour parts that lie outside of the tolerances
    *分割提取出距离小于指定最小距离的轮廓部分
    segment_contour_attrib_xld (OuterContourWithWidth, OuterContourPartToNarrow, 'distance', 'or', 0, MinWidth)
    length_xld (OuterContourPartToNarrow, Length1)
    *分割提取出距离大于指定距离的轮廓部分
    segment_contour_attrib_xld (OuterContourWithWidth, OuterContourPartToWide, 'distance', 'or', MaxWidth, 10000)
    length_xld (OuterContourPartToWide, Length2)
    
    * 检查轮廓本身的平滑度
    * Check, if the contours are sufficiently smooth by
    * comparing each contour with a smoothed version of itself
    smooth_contours_xld (OuterContour, OuterContourSmooth, 11)
    smooth_contours_xld (InnerContour, InnerContourSmooth, 11)
    distance_contours_xld (OuterContour, OuterContourSmooth, OuterContourWithDistance, 'point_to_segment')
    distance_contours_xld (InnerContour, InnerContourSmooth, InnerContourWithDistance, 'point_to_segment')
    * Get the contour parts that lie outside of the tolerances
    segment_contour_attrib_xld (OuterContourWithDistance, OuterContourDefect, 'distance', 'or', SmoothnessTolerance, 100)
    segment_contour_attrib_xld (InnerContourWithDistance, InnerContourDefect, 'distance', 'or', SmoothnessTolerance, 100)
    * 
    * Get pointwise distances for debugging
    get_contour_attrib_xld (OuterContourWithWidth, 'distance', FrameWidth)
    get_contour_attrib_xld (OuterContourWithDistance, 'distance', InnerDistances)
    get_contour_attrib_xld (InnerContourWithDistance, 'distance', OuterDistances)
    *
  
    * Display results
    dev_display (Image)
    disp_message (WindowHandle, 'Inspect frame of phone camera (image ' + I + '/' + NumImages + ')', 'window', 12, 12, 'black', 'true')
    count_obj (OuterContourPartToNarrow, NumTooNarrow)
    count_obj (OuterContourPartToWide, NumTooWide)
    count_obj (OuterContourDefect, NumInnerDefects)
    count_obj (InnerContourDefect, NumOuterDefects)
    if (NumTooNarrow + NumTooWide + NumInnerDefects + NumOuterDefects == 0)
        OK := 1
        disp_message (WindowHandle, 'Frame OK', 'window', 50, 12, 'forest green', 'true')
    else
        OK := 0
        disp_message (WindowHandle, 'Frame not OK', 'window', 50, 12, 'red', 'true')
    endif
    * 
    dev_set_line_width (1)
    dev_set_color (Colors[1])
    dev_display (OuterContour)
    dev_display (InnerContour)
    dev_set_line_width (5)
    dev_set_color (Colors[2])
    dev_display (OuterContourPartToNarrow)
    dev_set_color (Colors[3])
    dev_display (OuterContourPartToWide)
    dev_set_color (Colors[4])
    dev_display (OuterContourDefect)
    dev_set_color (Colors[4])
    dev_display (InnerContourDefect)
    disp_message (WindowHandle, Legend, 'window', 500, 12, Colors, 'false')
    if (I < NumImages)
        disp_continue_message (WindowHandle, 'black', 'true')
        stop ()
    endif
endfor