計算任意矩形的四個角點座標,基本數學方法利用到了初中高中數學知識:正弦定理和餘弦定理
一、基礎知識
1、halcon的矩形rectangle2定義
draw_rectangle2( : : WindowHandle : Row, Column, Phi, Length1, Length2)
smallest_rectangle2(Regions : : : Row, Column, Phi, Length1, Length2)
draw_rectangle2:窗口有個箭頭方向,這個方向就是矩形的角度Phi,和Phi方向一致的邊爲Length1,和Phi方向垂直的邊爲Length2
smallest_rectangle2:Length1爲長度較長的邊,Length2爲長度較短的邊,且滿足Phi爲長邊Length1方向的角度,角度範圍
- pi / 2 < Phi && Phi <= pi / 2
兩者相同點:Phi都是Length1的角度
兩者不同點:draw_rectangle2的Length1,Length2和Phi與邊長度無關,smallest_rectangle2與邊長度有關
2、正弦定理和餘弦定理
二、計算任意矩形的四個角點座標
步驟
1、統一矩形描述
把rectangle2轉爲PI/2>Phi>PI/4,或者-PI/4>Phi>-PI/2,修改矩形的的描述方式,讓矩形的Phi較大,這樣保證矩形縱方向是Length1,橫方向是Length2,
2、計算點A座標
x=x(OM) - x(AM) = Length1*cos(angle) - Length2*sin(angle)---------------------1.1
y=y(ON) + y(AN) = Length1*sin(angle) + Length2*cos(angle)---------------------1.2
設xLengh1 = Length1*cos(angle)
xLength2 = Length2*sin(angle)
yLength1 = Length1*sin(angle)
yLength2 = Length2*cos(angle)
簡化1.1和1.2爲
x = xLength1 - xLength2------------------------------------------1.3
y = yLength1 + yLength2------------------------------------------1.4
即A(xLength1 - xLength2, yLength1 + yLength2 )
同理,可以計算出B,C,D點的座標,過程中要考慮到Phi有正負之分
詳細代碼如下
* ****************************************
* * 求rectangle2的四個直角點
* * 0********|*********2
* * *********|**********
* * *********|**********
* * *********|**********
* * *********|**********
* * *********|**********
* * 1********|*********3
* *注:以與水平方向所成角度較大的邊中線爲軸線
* ****************************************
pi := acos(0)*2
if (phi >= 0 and phi < pi/4)
phi := phi - pi/2
Tem := length1
length1 := length2
length2 := Tem
elseif (phi > -pi/4 and phi < 0)
phi := phi + pi/2
Tem := length1
length1 := length2
length2 := Tem
endif
*
if (phi >= 0)
la := phi ///63
lb := la - pi/2 ////-26
tuple_tan (la, tem1)
tuple_tan (lb, tem2)
tuple_sqrt ((length1 * length1) / (1 + tem1 * tem1), xLength1)
tuple_sqrt ((length2 * length2) / (1 + tem2 * tem2), xLength2)
tuple_sqrt ((tem1*tem1*length1*length1) / (1 + tem1 * tem1), yLength1)
tuple_sqrt ((tem2 * tem2 * length2 * length2) / (1 + tem2 * tem2), yLength2)
* 左上
gen_cross_contour_xld (Cross, 1, columnCenter + xLength1- xLength2, 6, 0.785398)
mColumnUpLeft := columnCenter + xLength1 - xLength2
nRowUpLeft := rowCenter - yLength1 - yLength2
* 左下
mColumnDownLeft := columnCenter - xLength1 - xLength2
nRowDownLeft := rowCenter + yLength1 - yLength2
* 右上
mColumnUpRight := columnCenter + xLength1 + xLength2
nRowUpRight := rowCenter - yLength1 + yLength2
* 右下
mColumnDownRight := columnCenter - xLength1 + xLength2
nRowDownRight := rowCenter + yLength1 + yLength2
else
la := phi
lb := la - pi/2
tuple_tan (la, tem1)
tuple_tan (lb, tem2)
tuple_sqrt ((length1 * length1) / (1 + tem1 * tem1), xLength1)
tuple_sqrt ((length2 * length2) / (1 + tem2 * tem2), xLength2)
tuple_sqrt ((tem1*tem1*length1*length1) / (1 + tem1 * tem1), yLength1)
tuple_sqrt ((tem2 * tem2 * length2 * length2) / (1 + tem2 * tem2), yLength2)
* 左上
mColumnUpLeft := columnCenter - xLength1 - xLength2
nRowUpLeft := rowCenter - yLength1 + yLength2
* disp_cross (3600, nRowUpLeft, mColumnUpLeft, 16, 0)
* 左下
mColumnDownLeft := columnCenter + xLength1 - xLength2
nRowDownLeft := rowCenter + yLength1 + yLength2
* disp_cross (3600, nRowDownLeft, mColumnDownLeft, 16, 0)
* 右上
mColumnUpRight := columnCenter - xLength1 + xLength2
nRowUpRight := rowCenter - yLength1 - yLength2
* 右下
mColumnDownRight := columnCenter + xLength1 + xLength2
nRowDownRight := rowCenter + yLength1 - yLength2
endif
row := []
column := []
row[0] := nRowUpLeft
column[0] := mColumnUpLeft
row[1] := nRowDownLeft
column[1] := mColumnDownLeft
row[2] := nRowUpRight
column[2] := mColumnUpRight
row[3] := nRowDownRight
column[3] := mColumnDownRight
return ()
運行效果圖如下
注:代碼裏面推導過程稍有不同,用到了tan(angle)=sin(angle)/cos(angle),最終結果都是一樣的;基於這個方法,可以做很多算法,比如Blob粗定位,Blob精定位,直線濾波等;
因爲方法沒有引用其他方法,上述代碼就是所有源碼,這裏就不上傳源碼
如需要hdvp函數請留言個人郵箱
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版權聲明:本文爲CSDN博主「谷棵」的原創文章,遵循 CC 4.0 BY-SA 版權協議,轉載請附上原文出處鏈接及本聲明。
原文鏈接:https://blog.csdn.net/gukewee/article/details/105787343