基于Matlab的点到任意直线的投影点坐标的实现

uqHZau

【写在前面】因为图像坐标系和我们平时用的直角坐标系还是有不同的。因此在求点到直线投影点坐标的时候，不敢随便把直线用点斜式表示。为此采用向量的方法求投影点。

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5 R3 {- \( A8 H" q' x1 y! }% l8 o代码实现
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function proj_point = ProjPoint( point,line_p )
x1 = line_p(1);
y1 = line_p(2);
x2 = line_p(3);
5 t2 V. N6 F% C2 j2 ly2 = line_p(4);

x3 = point(1);
y3 = point(2);

; G5 T; C+ W5 _( D" @& xyk = ((x3-x2)*(x1-x2)*(y1-y2) + y3*(y1-y2)^2 + y2*(x1-x2)^2) / (norm([x1-x2,y1-y2])^2);
/ O+ w3 Y* w# |8 Y+ G0 S  R+ Lxk = ((x1-x2)*x2*(y1-y2) + (x1-x2)*(x1-x2)*(yk-y2)) / ((x1-x2)*(y1-y2));

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2 m9 G+ f- U2 V; b5 @3 {if x1 == x2
) U+ U, Y2 A7 P7 J6 Q    xk = x1;
end
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if y1 == y2
    xk = x3;
end

proj_point = [xk,yk];
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end

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ybing12

这个代码详细