Coordinate system

Define the centre pixel of the detector roi as x, y = (0, 0), for a sample translation of 0 and with no aberrations:

x_map[(roi[1]-roi[0])//2] = 0
y_map[(roi[3]-roi[2])//2] = 0

Basis vectors \(\mathbf{b}\) give the mapping of sample shifts in x-y lab coordinates (\(\Delta \mathbf{x}\)) to the slow scan and fast scan axes of the detector (\(\Delta \mathbf{x}_\text{D} = [\Delta x_{ss}, \Delta x_{fs}]\)):

\[\begin{split}\begin{align} \Delta x_{ss} &= \frac{\mathbf{b}_{ss} \cdot \Delta \mathbf{x}_{xy}}{\text{x_pixel_size}} \\ \Delta x_{fs} &= \frac{\mathbf{b}_{fs} \cdot \Delta \mathbf{x}_{xy}}{\text{y_pixel_size}} \end{align}\end{split}\]