Typo in Readme.md

[kilmarnock]

Hi!
Thank you for the implementation.

In the Readme.md, you say

DSO computes the camera matrix K as

K(0,0) = width * fx
K(1,1) = width * fy
K(0,2) = width * cx - 0.5
K(1,2) = width * cy - 0.5

Should be

float fx = inputCalibration[0] * in_width;

    float fy = inputCalibration[1] * in_height;
    float cx = inputCalibration[2] * in_width - 0.5;
    float cy = inputCalibration[3] * in_height - 0.5;

resp.

K(0,0) = width * fx
K(1,1) = height * fy
K(0,2) = width * cx - 0.5
K(1,2) = height * cy - 0.5

[NikolausDemmel]

See #72