First, draw a regular rectangle, mark it, and check if it is a regular rectangle, if not, do the following correction:
1‧Correct the rectangle to be a regular rectangle.
Correction: There are three types of correction (include: barrel correction, trapezoid correction, and parallelogram correction).
Barrel Correction
Input a square, the output become as below:
Trapezoid Correction
Input a square, the output become as below:
X value is negative |
X value is positive |
|
|
|
|
Y value is negative |
Y value is positive |
|
|
|
|
Parallelogram Correction
Input a square, the output become as below:
X value is negative |
X value is positive |
|
|
|
|
Y value is negative |
Y value is positive |
|
|
|
|
2‧Adjust the rectangle to its right size.
Scale:If the rectangle size does not match, adjust the scale value.
3‧Adjust the rectangle to the right position
Offset:If the position of the rectangle does not place in the right position, adjust the offset value.