Image distortion system and method
A method and system of distorting an image, particularly but not solely designed for magnifying parts of an image more than the remainder of the image. The method comprises the steps of maintaining in computer memory a set of base data values representing an image to be subjected to a transformation function; calculating a non identity approximation of the transformation function; retrieving from computer memory one or more of the base data values; calculating an intended magnification value (M c ) for one or more of the retrieved base data values; calculating an estimated magnification value (M s ) for one or more of the retrieved base data values; storing in computer memory the estimated magnification values as a set of transformed data values representing the transformed image; calculating the difference (M E ) between the intended magnification value(s) and the estimated magnification value(s); and repeating steps (c) to (g) until M E is less than a predefined threshold.
1. An image distortion method comprising the steps of:
(a) maintaining in computer memory a set of base data values representing an image to be subjected to a transformation function;
(b) calculating an initial non identity approximation of the transformation function;
(c) retrieving from computer memory one or more of the base data values;
(d) calculating an intended magnification value (M c ) for one or more of the retrieved base data values;
(e) calculating an estimated magnification value (M g ) for one or more of the retrieved base data values;
(f) storing in computer memory the estimated magnification values as a set of transformed data values representing the transformed image;
(g) calculating a difference (M E ) between the estimated magnification value(s) and the intended magnification value(s); and
(h) repeating steps (c) to (g) until the difference M E is less than a predefined threshold.
2. The image distortion method as claimed in claim 1 wherein the step of calculating the initial non identity approximation of the transformation function further comprises the steps of:
(a) defining an approximating function G(p) to approximate the transformation function, the approximating function including one or more parameters;
(b) defining an initial value of one of the parameters (p);
(c) calculating a maximal value of the derivative of the approximating function G(p) using the parameter p;
(d) calculating a maximal intended magnification value using the parameter p;
(e) calculating a difference between the maximal value of the derivative of G(p) and the maximal value of the intended magnification value;
(f) adjusting the value of the parameter p; and
(g) repeating steps (c) to (f) until the difference between the maximal value of the derivative of G(p) and the maximal value of the intended magnification value is less than a pre-defmned threshold.
3. An image distortion system for subjecting a set of base data values representing an image to a transformation function, the system comprising:
a transformation approximation component configured to calculate an initial non identity approximation of the transformation function;
an intended magnification calculator configured to calculate an intended magnification value (M c ) for one or more of the base data values;
an estimated magnification calculator configured to calculate an estimated magnification value (M s ) for one or mare of the data base values; and
a convergence measurer configured to repeat the calculation of the difference (M E ) between the estimated magnification value and the intended magnification value until (M E ) is less than a pre-defined threshold.