Projection system, projection apparatus and calibrating method for displayed image thereof

1. A calibration method for a displayed image, suitable for a projection system comprising a projection apparatus, an image capturing apparatus, and an arithmetic device, the calibration method comprising:

by the projection apparatus, projecting a calibration image, wherein the calibration image comprises at least four identification patterns;

by the image capturing apparatus, providing multi-axis angle information and capturing a captured image;

by the arithmetic device, calculating a reference region range in the captured image according to the multi-axis angle information and calculating coordinate conversion information according to the identification patterns in the calibration image and a plurality of identification patterns in the captured image;

by the arithmetic device, calculating boundary calibration information according to a plurality of reference coordinate values on the reference region range and the coordinate conversion information; and

by the projection apparatus, adjusting a size of an imaged image according to the boundary calibration information and the coordinate conversion information.

2. The calibration method for the displayed image as claimed in claim 1 , further comprising: by the arithmetic device, establishing first coordinate information according to the identification patterns of the calibration image, establishing second coordinate information according to the identification patterns in the captured image, and calculating the coordinate conversion information according to the first coordinate information and the second coordinate information.

3. The calibration method for the displayed image as claimed in claim 2 , further comprising: by the arithmetic device, establishing a first coordinate system according to the calibration image and establishing the first coordinate information according to coordinate values of geometric centers of the identification patterns of the calibration image in the first coordinate system.

4. The calibration method for the displayed image as claimed in claim 2 , further comprising: by the arithmetic device, establishing a second coordinate system according to the captured image and establishing the second coordinate information according to coordinate values of geometric centers of the identification patterns in the captured image in the second coordinate system.

5. The calibration method for the displayed image as claimed in claim 4 , further comprising: by the arithmetic device, calculating the reference coordinate values of a plurality of corners of the reference region range in the second coordinate system and converting the reference coordinate values according to the coordinate conversion information to obtain the boundary calibration information.

6. The calibration method for the displayed image as claimed in claim 5 , further comprising: by the projection apparatus, performing a shrinking or enlarging operation on an original size of image data of the imaged image according to the boundary calibration information, so as to obtain adjusted image data, and performing a projecting operation according to the adjusted image data.

7. The calibration method for the displayed image as claimed in claim 1 , further comprising: providing a multi-axis angle detector by using the image capturing apparatus, and detecting a static gravity state of the image capturing apparatus by using the multi-axis angle detector, so as to generate the multi-axis angle information.

8. The calibration method for the displayed image as claimed in claim 1 , further comprising: by the arithmetic device, adjusting at least one of a position and a size of the reference region range according to positions of the identification patterns in the captured image.

9. The calibration method for the displayed image as claimed in claim 1 , wherein the identification patterns are at a plurality of corners of the calibration image.

10. A projection system, comprising:

a projection apparatus, configured to project a calibration image and adjust a size of an imaged image according to boundary calibration information and coordinate conversion information, wherein the calibration image includes at least four identification patterns;

an image capturing apparatus, configured to provide multi-axis angle information and capture a captured image; and

an arithmetic device, coupled to the projection apparatus and the image capturing apparatus, and configured to calculate a reference region range in the captured image according to the multi-axis angle information and calculate the boundary calibration information according to a plurality of reference coordinate values on the reference region range and the coordinate conversion information,

wherein the arithmetic device is configured to calculate the reference region range according to the multi-axis angle information, and

wherein the arithmetic device is configured to calculate the coordinate conversion information according to the identification patterns of the calibration image and a plurality of identification patterns in the captured image.

11. The projection system as claimed in claim 10 , wherein the arithmetic device is configured to establish first coordinate information according to the identification patterns of the calibration image, establish second coordinate information according to the identification patterns in the captured image, and calculate the coordinate conversion information according to the first coordinate information and the second coordinate information.

12. The projection system as claimed in claim 11 , wherein the arithmetic device is configured to establish a first coordinate system according to the calibration image and establish the first coordinate information according to coordinate values of geometric centers of the identification patterns of the calibration image in the first coordinate system.

13. The projection system as claimed in claim 11 , wherein the arithmetic device is configured to establish a second coordinate system according to the captured image and establish the second coordinate information according to coordinate values of geometric centers of the identification patterns in the captured image in the second coordinate system.

14. The projection system as claimed in claim 13 , wherein the arithmetic device is configured to calculate the reference coordinate values of a plurality of corners of the reference region range in the second coordinate system and convert the reference coordinate values according to the coordinate conversion information to obtain the boundary calibration information.

15. The projection system as claimed in claim 14 , wherein the projection apparatus is configured to perform a shrinking or enlarging operation on an original size of image data of the imaged image according to the boundary calibration information, so as to obtain adjusted image data, and performs a projecting operation according to the adjusted image data.

16. The projection system as claimed in claim 10 , wherein the image capturing apparatus comprises a multi-axis angle detector, wherein:

the multi-axis angle detector is configured to detect a static gravity state of the image capturing apparatus,

wherein the projection system is configured to generate the reference region range by further referring to the static gravity state of the image capturing apparatus.

17. The projection system as claimed in claim 10 , wherein the arithmetic device is further configured to adjust at least one of a position and a size of the reference region range according to positions of the identification patterns in the captured image.

18. The projection system as claimed in claim 10 , wherein the image capturing apparatus further comprises a display screen and a signal transmission interface, wherein:

the display screen is configured to display the reference region range; and

the signal transmission interface is configured to transmit the coordinate conversion information to the projection apparatus.

19. The projection system as claimed in claim 10 , wherein the image capturing apparatus and the arithmetic device are disposed in a handheld electronic apparatus.

20. A projection apparatus, comprising an image capturing apparatus and an arithmetic device, wherein:

the image capturing apparatus is configured to provide multi-axis angle information and capture a captured image; and

the arithmetic device is coupled to the image capturing apparatus, and is configured to control a projection lens to project a calibration image and adjust a size of an imaged image according to boundary calibration information and coordinate conversion information,

wherein the calibration image includes at least four identification patterns,

wherein the arithmetic device is configured to calculate the boundary calibration information according to a plurality of reference coordinate values on the reference region range and the coordinate conversion information,

wherein the arithmetic device is configured to calculate the reference region range according to the multi-axis angle information, and

wherein the arithmetic device is configured to calculate the coordinate conversion information according to the identification patterns of the calibration image and a plurality of identification patterns in the captured image.