There are five steps in converting a digital array into an image on the sky:

- 1.
- (optional) Transform from actual image pixel numbers to those that would be observed by an ideal instrument.
- 2.
- Transform from the origin and axes of the instrumental coordinate matrix system to the origin and axes of a set of projected sky coordinates.
- 3.
- Convert the scale along each axis from pixel to physical values, still in the projection plane.
- 4.
- Determine the projection of the sky onto the coordinate plane of the digital array and deproject from the array plane onto the sky.
- 5.
- Transform from sky coordinates derived by deprojection to a standard celestial coordinate system.

- Pixel Regularization
- Transforming to Projected Sky Coordinate
- From Pixel to Physical Values
- Deprojection
- Conversion to Standard Celestial Coordinates