Method for correcting for distortion of projected image, program for correcting image distortion, and projection-type image display device

A distortion correction program to have a computer perform a method for correcting for distortion of a projected image caused by projecting an image with a projection optical axis being tilted from normal to a screen, said method comprising:

• a first step of displaying a plurality of correction function indicating marks corresponding to a plurality of correction functions to make corrections to specified points as correction objects in said projected image;
• a second step of displaying said correction function indicating marks corresponding to said correction functions selected by an operator on said screen in a highlighted manner;
• a third step of moving said specified points as correction objects of the selected correction functions on said screen according to an instruction of said operator and of calculating a correction parameter corresponding to a range of the motion;
• and
• a fourth step of correcting said projected image based on said correction parameter.

A projection-type image display device comprising:

• an operating unit having cursor keys to provide instructions for up and down or left and right movements;
• a displaying unit to provide, on a screen, a plurality of correction function indicating marks corresponding to a plurality of correction functions to make corrections to specified points as correction objects of said projected image used to correct for distortion of a projected image caused by projecting an image with a projection optical axis being tilted from normal to said screen;
• a controlling unit to control said displaying unit so as to display said correction function indicating marks corresponding to said correction functions being selected by operations of said operating unit on said screen in a highlighted manner, to move said specified points as correction objects to be corrected by said correction function being selected on said screen according to an instruction provided through operations of said operating unit, and to calculate a correction parameter corresponding to a range of the motion;
• and
• a correcting unit to make corrections to said projected image based on said correction parameters.