Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An audio signal processing device and an audio signal adjusting method thereof. The audio signal processing device includes a gain determining circuit and an audio signal processing circuit. The gain determining circuit receives an analog audio signal. The gain determining circuit determines a gain based on a difference between a predefined threshold and an amplitude of the analog audio signal in response to detecting that a current sampling amplitude of the analog audio signal is greater than the predefined threshold. The audio signal processing circuit is coupled to the gain determining circuit and receives the analog audio signal and the gain. The audio signal processing circuit attenuates the analog audio signal according to the gain to generate an output audio signal.

Abstract: An audio signal processing device and an audio signal adjusting method thereof. The audio signal processing device includes a gain determining circuit and an audio signal processing circuit. The gain determining circuit receives an analog audio signal. The gain determining circuit determines a gain based on a difference between a predefined threshold and an amplitude of the analog audio signal in response to detecting that a current sampling amplitude of the analog audio signal is greater than the predefined threshold. The audio signal processing circuit is coupled to the gain determining circuit and receives the analog audio signal and the gain. The audio signal processing circuit attenuates the analog audio signal according to the gain to generate an output audio signal.