Halcon讀取dxf檔案生成xld，然後實作點坐标周遊/縮放/鏡像/求最大面積等操作(★firecat推薦★)

Halcon中的坐标系的原點在左上角，而一般二維平面坐标系的原點在左下角。

請注意，使用read_polygon_xld_dxf讀取DXF檔案所産生的幾何資訊與使用read_contour_xld_dxf讀取檔案完全相同。 但是，資料結構不同。

draw_xld_mod — Interactive modification of a contour.

read_contour_xld_dxf (Contours, 'AAA.dxf', 'min_num_points', 100, DxfStatus)
hom_mat2d_identity (HomMat2DIdentity)
get_image_size (Image, Width, Height)
hom_mat2d_scale (HomMat2DIdentity, 0.06, 0.06, Height/2.0, Width/2.0, HomMat2DScale)
affine_trans_contour_xld(Contours, ContoursAffinTrans1, HomMat2DScale)      

1、Halcon讀取dxf檔案，得到的是dxf檔案的機械坐标數值，舉例說明：

*Create locally deformable model
read_contour_xld_dxf (DxfContours, 'C:/Users/firecat/neiyi1.dxf', [], [], DxfStatus)
*合并鄰近的XLD,使得細小線段拼接起來
union_adjacent_contours_xld (DxfContours, UnionContours, 10, 1, 'attr_keep')
count_obj(UnionContours, NumberContours)
    for i := 1 to NumberContours by 1
        select_obj (UnionContours, ObjectSelected, i)
        length_xld (ObjectSelected, Length) 
        get_contour_xld (ObjectSelected, row, col)
    endfor
create_local_deformable_model_xld (UnionContours, 'auto', rad(-10), rad(20), 'auto', 1, 1, 'auto', 
1, 1, 'auto', 'auto', 'ignore_local_polarity', 5, [], [], ModelID)
get_deformable_model_contours (ModelContours, ModelID, 1)      

2、如何實作xld的縮放？通過縮放XLD中每個點的坐标值來實作。xld需要先縮放，後拼接！

read_contour_xld_dxf (DxfContours, 'C:/Users/firecat/neiyi1.dxf', [], [], DxfStatus)
Scale := 4
count_obj(DxfContours, NumberContours)
gen_empty_obj (ScaleContours)
for i := 1 to NumberContours by 1
    select_obj (DxfContours, ObjectSelected, i)
    get_contour_xld (ObjectSelected, row, col)
    Row1 := []
    Col1 := []
    for j := 0 to |row|-1 by 1   
        Row1:=[Row1, row[j] * Scale]
        Col1:=[Col1, col[j] * Scale]
    endfor      

   *判斷輪廓是不是閉合，如果是閉合的，那麼使最後一個點與第一個點重合（即讓縮放後的XLD也閉合）

   test_closed_xld (ObjectSelected, IsClosed)

   if (IsClosed == 1)

       Row1:=[Row1, row[0] * Scale]

       Col1:=[Col1, col[0] * Scale]

   endif

   gen_contour_polygon_xld (Contour1, Row1, Col1)

   smooth_contours_xld (Contour1, SmoothedContours, 5)

   concat_obj (ScaleContours, SmoothedContours, ScaleContours)

endfor

*xld拼接

union_adjacent_contours_xld (ScaleContours, UnionContours, 10, 1, 'attr_keep')

其中：

get_contour_xld (Contour, Row, Col)是得到XLD中的一系列點；

gen_contour_polygon_xld (Contour1, Row1, Col1)是通過一系列點重建XLD。

3、鏡像（因為DXF坐标系和halcon坐标系存在上下翻轉的對應關系）

*使用仿射變換實作鏡像,這裡是上下翻轉

hom_mat2d_identity (HomMat2DIdentity)

hom_mat2d_reflect (HomMat2DIdentity, 0, 0, 0, 32, HomMat2DReflect)

affine_trans_contour_xld (UnionContours, ContoursAffinTrans, HomMat2DReflect)

hom_mat2d_reflect算子的參數說明：

Px (input_control)  point.x → (real / integer)

First point of the axis (x coordinate).

Default value: 0

Suggested values: 0, 16, 32, 64, 128, 256, 512, 1024

Py (input_control)  point.y → (real / integer)

First point of the axis (y coordinate).

Qx (input_control)  point.x → (real / integer)

Second point of the axis (x coordinate).

Default value: 16

Qy (input_control)  point.y → (real / integer)

Second point of the axis (y coordinate).

Default value: 32

4、更詳細的實踐

read_contour_xld_dxf (DxfContours, 'C:/Users/firecat/Downloads/1.dxf', [], [], DxfStatus)
*合并鄰近的XLD,使得細小線段拼接起來
union_adjacent_contours_xld (DxfContours, UnionContours, 5, 1, 'attr_keep')
*找出面積最大的輪廓,方法1
count_obj(UnionContours, NumberContours)
maxArea := 0
index := 0
for i := 1 to NumberContours by 1
    select_obj (UnionContours, ObjectSelected, i)
    length_xld (ObjectSelected, Length) 
    area_center_xld (ObjectSelected, Area, Row1, Column1, PointOrder)
    if (Area > maxArea)
        maxArea := Area
        index := i
    endif
    get_contour_xld (ObjectSelected, row, col)
endfor
select_obj (UnionContours, MaxAreaSelected, index)
get_contour_xld (MaxAreaSelected, Row2, Column2)
stop()
*找出面積最大的輪廓,方法2
area_center_xld (UnionContours, Area, Row, Column, PointOrder)
*先将Area中各元素按升序排序，然後将排序後的每一個Area分别在原Area元組中的索引放在元組Indices 中
tuple_sort_index (Area, Indices)
Num := |Indices|
*tuple的下标從0開始計數;Obj的下标從1開始計數;
index := Indices[Num-1] + 1
select_obj (UnionContours, MaxAreaSelected, Indices[Num-1] + 1)
get_contour_xld (MaxAreaSelected, Row1, Col1)
stop()
*把最大輪廓裁剪出來,生成圖檔
gen_region_contour_xld (MaxAreaSelected, Region, 'filled')
gen_image_const (NewImage, 'byte', 1000, 1000)
*Create an image with a specified constant gray value
gen_image_proto (NewImage, ImageCleared1, 255)
*Paint regions into an image
paint_region (Region, ImageCleared1, ImageResult, 0, 'fill')
write_image (ImageResult, 'jpeg', 0, 'D:/1.jpg')      

再優化更新一稿：

read_contour_xld_dxf (DxfContours, 'C:/Users/firecat/Downloads/match/neiyi/M-OK180503.dxf', [], [], DxfStatus)
*合并鄰近的XLD,使得細小線段拼接起來
union_adjacent_contours_xld (DxfContours, UnionContours, 5, 1, 'attr_keep')
*找出面積最大的輪廓,方法1
count_obj(UnionContours, NumberContours)
maxArea := 0
index := 0
for i := 1 to NumberContours by 1
    select_obj (UnionContours, ObjectSelected, i)
    length_xld (ObjectSelected, Length) 
    area_center_xld (ObjectSelected, Area, Row1, Column1, PointOrder)
    if (Area > maxArea)
        maxArea := Area
        index := i
    endif
    get_contour_xld (ObjectSelected, row, col)
endfor
select_obj (UnionContours, MaxAreaSelected, index)
get_contour_xld (MaxAreaSelected, Row2, Column2)
stop()
*找出面積最大的輪廓,方法2
area_center_xld (UnionContours, Area, Row, Column, PointOrder)
*先将Area中各元素按升序排序，然後将排序後的每一個Area分别在原Area元組中的索引放在元組Indices 中
tuple_sort_index (Area, Indices)
Num := |Indices|
*tuple的下标從0開始計數;Obj的下标從1開始計數;
index := Indices[Num-1] + 1
select_obj (UnionContours, MaxAreaSelected, Indices[Num-1] + 1)
get_contour_xld (MaxAreaSelected, Row1, Col1)
stop()
*求出外接矩形
shape_trans_xld(MaxAreaSelected, XLDTrans, 'rectangle1')
area_center_xld (XLDTrans, Area, Row2, Column2, PointOrder)
smallest_rectangle1_xld (MaxAreaSelected, Row11, Column11, Row21, Column21)
width := Column21 - Column11 + 1
height := Row21 - Row11 + 1
*建立圖檔,圖檔左上角是零點,準備用來存放最大面積
gen_image_const (NewImage, 'byte', width, height)
area_center (NewImage, Area, Row1, Column1)
*Create an image with a specified constant gray value
gen_image_proto (NewImage, ImageCleared, 255)
*仿射變換,讓外接矩形的最大面積和圖檔重合
hom_mat2d_identity (HomMat2DIdentity)
hom_mat2d_translate (HomMat2DIdentity, Row1 - Row2, Column1 - Column2, HomMat2DTranslate)
affine_trans_contour_xld (MaxAreaSelected, ContoursAffineTrans, HomMat2DTranslate)
*把最大輪廓區域裁剪出來
gen_region_contour_xld (ContoursAffineTrans, Region, 'filled')
*Paint regions into an image
paint_region (Region, ImageCleared, ImageResult, 0, 'fill')
*注意儲存路徑的斜杆,是/
write_image (ImageResult, 'jpeg', 0, 'D:/test.jpg')
stop()