Halcon's region: features of multiple regions (5)

One 、 summary

   Some areas generate , Beginners need everyone to try , This is not just a matter of enhancing the image , And understand Halcon The process of ability . This paper introduces several applications in numerical image analysis , More useful domain operators . Please share ！

This article is dedicated to the experimental verification of the attribute of the region . It is a series with the previous articles , Include ：

 halcon Area of ： Area （Region） Contour operator on

 halcon Area of ： Multiple areas （Region） Generate （3） 

 halcon Area of ： Multiple areas （Region） Generate （4）_ 

halcon Area of ：get_region_chain and get_region_contour_ 

 

Two 、 Characteristics of the area

2.1 area_center Regional Center

• area_center:  function ： The area of an area （ size ） And the center .

area_center(regin, ares,Row1, Column1)

set_color(3600,'red')
read_image (Image, 'f:/images/DOTS/block.jpg')
rgb1_to_gray(Image,gray)

get_image_size(gray,width,height)
 
fast_threshold (gray,regin,0, 50 , 7)
area_center(regin,ares,Row1, Column1)

2.2 circularity Calculate roundness

• circularity： function ： Shape coefficient that affects the similarity between a region and a circle .

circularity(regin, Circularity)

Roundness range ：0-1

set_color(3600,'red')
read_image (Image, 'f:/images/DOTS/many_block.jpg')
rgb1_to_gray(Image,gray)

get_image_size(gray,width,height)
fast_threshold (gray,regin,0, 50 , 7)

connection(regin, ConnectedRegions)
circularity(ConnectedRegions, Circularity)

  Roundness is ：0.395611、0.64085、0.949253、0.529871; It seems to be consistent from a visual point of view .

2.3. compactness Tightness

• compactness： function ： The shape factor that affects the density of an area .

Tightness ：3.43204、1.25161、1.10005、2.074

Tightness and roundness are similar , and , The circle has the highest compactness .

2.4. connect  and_holes Number of connections and holes

  function ： Number of connections and interrupts .

connect_and_holes(regin, NumConnected, NumHoles)

set_color(3600,'red')
read_image (Image, 'f:/images/DOTS/block.jpg')
rgb1_to_gray(Image,gray)

get_image_size(gray,width,height)
fast_threshold (gray,regin,0, 50 , 7)
connect_and_holes(regin, NumConnected, NumHoles)

Connect as 2, Holes are 2 Here is the picture . 

2.5. contlength Get the contour length outside the region

  function ： Describe an area outline (contour) The length of .

contlength(regin,ContLength)

Note here , Let's verify ,gen_contour_region_xld and contlength(regin, ContLength) The length of the two outer contours is inconsistent ：

gen_contour_region_xld (regin, Contours, 'border')
contlength(regin, ContLength)

2.6. Convexity of region

convexity   function ： The shape coefficient that affects the convexity of a region .

  result ：0.539397、0.991524、0.994038、0.72976, You can see , A circle is almost as convex as a square .

2.7. diameter  region

  function ： The maximum distance between two boundary points in an area .

diameter_region(ConnectedRegions,row1,col1,row2,col2,dim)

set_color(3600,'red')
read_image (Image, 'f:/images/DOTS/many_block.jpg')
rgb1_to_gray(Image,gray)

get_image_size(gray,width,height)
fast_threshold (gray,regin,0, 50 , 7)
connection(regin, ConnectedRegions)
diameter_region(ConnectedRegions,row1,col1,row2,col2,dim)

Maximum diameter ：161.608、155.013、151.743、132.91 

2.8. eccentricity Ellipse parameters

  function ： The shape factor from the ellipse parameter .

eccentricity(Regions : : : Anisometry, Bulkiness, StructureFactor)

obviously Anisometry Is the ratio of major and minor axes ; above A Is the actually measured pixel area in the ellipse .Bulkiness Ratio of actual area to theoretical area .StructureFactor Structural factor ,

2.9. elliptic  axis Similar ellipse

  function ： Parameters of similar ellipses .

2.10．euler_number Euler number

function ： Calculation Euler number . operator euler_number Calculate Euler number , That is, the difference between the number of connecting components and the number of holes .

such as ： The hole in the figure below （ The background is empty ）, It's a green number ; The connector of the foreground is four black areas ; So the Euler number is ：

Number（ Black connection 4 individual ）- empty （ white 5 individual ）=-1