Patent ID: 11877103
Assignee: ALI CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 5:
6. A projection device, comprising:
a projection module; and
an image processing circuit configured to:
obtain a plurality of target coordinates of a plurality of target vertexes based on a plurality of planes of a projection surface when the projection module performs projection toward the projection surface, wherein the plurality of planes are not coplanar with each other, and the plurality of target vertexes form a target polygon;
perform a first direction scaling process respectively on a plurality of first image portions of an original rectangular image and generate a trapezoidal image block, wherein the image processing circuit is further configured to:
obtain a plurality of first trapezoidal boundaries respectively corresponding to the plurality of first image portions according to a predetermined image boundary and a first coordinate component of each of the plurality of target coordinates; and
perform the first direction scaling process on the plurality of first image portions respectively according to the plurality of first trapezoidal boundaries and generate a plurality of second image portions, wherein the plurality of second image portions form the trapezoidal image block; and

perform a second direction scaling process respectively on a plurality of second image portions of the trapezoidal image block and generate a target image block aligned with the target polygon, wherein the image processing circuit is further configured to:
respectively extend two edges of the target polygon until the two edges intersect two reference line segments and obtain two second trapezoidal boundaries, wherein a bottom edge of the trapezoidal image block is perpendicular to bottom edges of the two second trapezoidal boundaries; and
perform the second direction scaling process on two of the plurality of second image portions respectively according to the two second trapezoidal boundaries to generate two sub-target image blocks, wherein the target image block comprises the two sub-target image blocks,

wherein the projection module projects an output image comprising the target image block onto the projection surface.