Correction information calculating device, image processing apparatus, image display system, and image correcting method

An image processing method comprising:

• calculating correction information representing a correspondence relationship between positions of pixels in an image projected onto projection areas of a projection surface from projectors each including an image forming element and positions of pixels in the image forming element;
• and
• correcting image data such that an image projected onto the projection surface by projectors based on the image data after correction approximately coincides with an image represented by the image data before correction by referring to correction information,
• wherein the calculating of correction information includes:
• acquiring correspondence information representing the correspondence relationship between identification patterns on the projection surface and the projectors projecting the identification patterns by comparing relative positions of identification diagrams in an array of a plurality of the identification patterns inside a photographed image, the photographed image acquired by photographing a plurality of the identification diagrams arranged on the projection surface when the identification patterns including the identification diagrams are projected from a plurality of the projectors and a disposition information representing a correspondence relationship between relative positions of the projection areas in an array of a plurality of the projection areas according to the plurality of the projectors and the projectors projecting an image onto the projection areas;
• and
• calculating the correction information, by a correction information calculating unit including a first pattern detecting unit and a second pattern detecting unit, which is different from first pattern detecting unit by:
• establishing a correspondence between a first projected pattern and a first projector based on a first diagram by the first pattern detecting unit, and
• determining the positions of a plurality of characteristic points in a second diagram different from the first diagram projected by the projector determined by the first pattern detecting unit by the second pattern detecting unit, wherein
• the correction information calculating unit calculates correction information by associating and comparing, based on the correspondence information, the positions of the plurality of characteristic points defined in original data of characteristic point patterns, including the plurality of the characteristic points, the original data being supplied to the projectors, and the positions of the plurality of characteristic points inside the photographed image acquired by photographing the characteristic point patterns being projected based on the original data, wherein
• the characteristic point patterns projected from the plurality of the projectors are photographed at the same time.