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An object is viewed by a camera with image size
640x480, focal length = 500 pixels
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The pose of the object (or model) with respect to the world is given by
H_m_w =
0.9254 0.0180 0.3785 0.5000
0.1632 0.8826 -0.4410 -0.5000
-0.3420 0.4698 0.8138 5.0000
0 0 0 1.0000
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The orientation of the camera is aligned with the world
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The origin of the camera is at world point = [0;0;-2]

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Draw (in 3D) the coordinate axes of the world, the camera, and the model clear all close all
% good idea to do these at the beginning of each program
% XYZ coordinate axes (first column is the origin).
Paxes = ...
[0 1 0 0;
0 0 1 0;
0 0 0 1;
1 1 1 1];
% Draw a dot at the world origin. This also opens a new figure.
plot3(0,0,0, '.' ); hold on
1 of 2
% Draw axes for the world frame.
P_w = Paxes; line([P_w(1,1) P_w(1,2)], [P_w(2,1) P_w(2,2)], [P_w(3,1) P_w(3,2)], 'Color' , 'r' ); line([P_w(1,1) P_w(1,3)], [P_w(2,1) P_w(2,3)], [P_w(3,1) P_w(3,3)], 'Color' , 'g' ); line([P_w(1,1) P_w(1,4)], [P_w(2,1) P_w(2,4)], [P_w(3,1) P_w(3,4)], 'Color' , 'b' ); text(P_w(1,1),P_w(2,1),P_w(3,1), '{W}' );
% Camera pose.
H_c_w = ...
[ 1 0 0 0;
0 1 0 0;
0 0 1 -2;
0 0 0 1];

% Draw axes for the camera frame.
P_w = H_c_w * Paxes; line([P_w(1,1) P_w(1,2)], [P_w(2,1) P_w(2,2)], [P_w(3,1) P_w(3,2)], 'Color' , 'r' ); line([P_w(1,1) P_w(1,3)], [P_w(2,1) P_w(2,3)], [P_w(3,1) P_w(3,3)], 'Color' , 'g' ); line([P_w(1,1) P_w(1,4)], [P_w(2,1) P_w(2,4)], [P_w(3,1) P_w(3,4)], 'Color' , 'b' ); text(P_w(1,1),P_w(2,1),P_w(3,1), '{C}' );
% Model pose.
H_m_w = [
0.9254 0.0180 0.3785 0.5000;
0.1632 0.8826 -0.4410 -0.5000;
-0.3420 0.4698 0.8138 5.0000;
0 0 0 1.0000];
2 of 2
% Draw axes for the model frame.
P_w = H_m_w * Paxes; line([P_w(1,1) P_w(1,2)], [P_w(2,1) P_w(2,2)], [P_w(3,1) P_w(3,2)], 'Color' , 'r' ); line([P_w(1,1) P_w(1,3)], [P_w(2,1) P_w(2,3)], [P_w(3,1) P_w(3,3)], 'Color' , 'g' ); line([P_w(1,1) P_w(1,4)], [P_w(2,1) P_w(2,4)], [P_w(3,1) P_w(3,4)], 'Color' , 'b' ); text(P_w(1,1),P_w(2,1),P_w(3,1), '{M}' );
% These options make the 3D display look nicer.
axis equal axis vis3d

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Create intrinsic camera matrix K
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Create extrinsic matrix Mext, representing the pose of the model with respect to camera
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Project the model points using p = K Mext P
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Write the points into a blank image
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Draw lines onto the image