Ali Corporation

Zhao-Dong Zhang

Lun Liang

Ben-Xiang Qu

A projection device and a keystone correction method thereof are provided. The keystone correction method is adapted for the projection device and includes the following steps. A first image is obtained. A first line-taking position parameter is determined according to a ratio of a first target edge length to a second target edge length. At least one line of input pixels disposed in a first direction is retrieved from the first image according to the first line-taking position parameter. A first scaling process related to the first direction is performed according to at least one line of input pixels of the first image, such that a line of output pixels of a second image disposed in the first direction is generated. The projection device projects the second image onto a projection screen to display a rectangular projected image.

Projection device and keystone correction method thereof

A projection device and a projection picture correction method thereof are provided. When the projection device performs projection toward a projection surface, a plurality of target coordinates of a plurality of target vertexes are obtained based on a plurality of planes of the projection surface. The plurality of planes are not coplanar with each other, and the plurality of target vertexes form a target polygon. A first direction scaling process is performed respectively on a plurality of first image portions of an original trapezoidal image and a trapezoidal image block is generated. A second direction scaling process is performed respectively on a plurality of second image portions of the trapezoidal image block and a target image block aligned with the target polygon is generated. An output image including the target image block is projected onto the projection surface.

Projection device and projection picture correction method thereof

A projection device and a projection image correction method are provided. Four target coordinates of four target vertices forming a target quadrilateral boundary are obtained. A first trapezoidal boundary is obtained according to a predetermined image boundary and a first coordinate component of each of the four target coordinates. At least one edge of the target quadrilateral boundary is extended until intersecting with at least one of two reference line segments to obtain a second trapezoidal boundary. Bases of the first trapezoidal boundary are perpendicular to bases of the second trapezoidal boundary. First direction scaling processing is performed according to the first trapezoidal boundary, and second direction scaling processing is performed according to the second trapezoidal boundary, to scale an original image into a target image block aligned with the target quadrilateral boundary in an output image. The projection device projects the output image to display a rectangular projection image.

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Guangdong, China

Zhao-Dong Zhang