optimization of perspective projection result

i have a 3d model in a coordinate system that i need to project on a 2d plane using perspective projection, i used this projection equation C*(RT * P') where C is the calibration matrix

[f 0 px
 0 f py
 0 0 1]

px and py are coordinat开发者_运维问答es of origin point i put them both by zero, R is the rotation matrix and T is the translation matrix i put them both in one matrix that represent both of them and i used a translation value of 3meters (in pixel value : 9448.82 approximately , not sure if this conversion is right) on Z-axis and 1 meter on Y axis, f is the focal length and i'm not sure of the value i used but i calculated it by this equation: f= (image width) * (image focal length) / (7.81) , i got the 7.81 value from my camera brand website as it is supposed to be an internal camera parameter and this is what i'm not sure if it is right.

this is a screenshot of the model that i'm trying to project.

and this is the model after projection ... it seems to me like it is scaled over X axis it doesn't feel like it's exactly the same model and after filling the gaps between the points by some filling algorithm :

here is the result it is more unlike the original model ... any help please about where the problem is so i can fix it .. thanks :)