Linking-up photographing system and control method for linked-up cameras thereof

A linking-up photographing system, comprising:

• a first camera configured to acquire a first image;
• a second camera configured to acquire a second image presenting a FOV which partially at least overlaps a FOV of the first image;
• a calibration processor configured to establish a control look-up table according to the first image and the second image;
• and
• a control processor configured to receive a designating command which specifies a ROI in the first image, and adjust a FOV of the second camera according to the ROI and the control look-up table, so as to control the second camera to photograph a view specified by the ROI, to obtain a third image,
• wherein the control processor looks up a capture position parameter corresponding to the ROI in the control look-up table according to a third central point of the ROI, and controls the second camera to obtain the third image according to the capture position parameter;
• wherein the second image comprises a second central point, the ROI comprises a plurality of boundary points, and when looking up the capture position parameter corresponding to the ROI in the control look-up table according to the third central point of the ROI, the control processor performs the following steps:
• calculating a third central mapping point of the second image corresponding to the third central point;
• calculating a plurality of boundary mapping points of the second image corresponding to the boundary points;
• calculating a scaling angle according to the boundary mapping points, the second central point and the third central mapping point;
• and
• looking up the capture position parameter corresponding to the ROI in the control look-up table according to the third central mapping point, wherein the capture position parameter comprises a tilt coefficient and a pan coefficient;
• and
• wherein when calculating the scaling angle according to the boundary points, the second central point and the third central mapping point, the control processor calculates a plurality of angles formed by the boundary mapping points, the second central point and the third central mapping point, and multiplies a maximum acute angle of the angles by 2 to obtain the scaling angle.

A control method of linked-up cameras, comprising:

• acquiring a first image via a first camera;
• acquiring a second image via a second camera, wherein a field of view (FOV) of the second image partially at least overlaps a FOV of the first image;
• establishing a control look-up table according to the first image and the second image;
• receiving a designating command which specifies a region of interest (ROI) in the first image;
• and
• adjusting a FOV of the second camera according to the ROI and the control look-up table, and then controlling the second camera to photograph a view specified by the ROI, to obtain a third image,
• wherein the ROI is circular and has a plurality of boundary points, the second image has a second central point, and the step of looking up the capture position parameter which corresponds to the ROI, in the control look-up table according to the third central point of the ROI comprises:
• calculating a second central mapping point of the first image corresponding to the second central point, and calculating a third central mapping point of the second image corresponding to the third central point;
• defining a first reference circle by setting the second central mapping point to be a center of circle and setting a distance between the second central mapping point and the third central point to be a radius, wherein the first reference circle joins two of the boundary points;
• calculating two boundary mapping points of the second image corresponding to the two boundary points joining the first reference circle;
• calculating a scaling angle according to the two boundary mapping points, the second central point and the third central mapping point;
• and
• looking up the capture position parameter which corresponds to the ROI, in the control look-up table according to the third central mapping point, wherein the capture position parameter comprises a tilt coefficient and a pan coefficient;
• and
• wherein the step of calculating the scaling angle according to the two boundary mapping points, the second central point and the third central mapping point comprises:
• calculating a plurality of angles formed by the two boundary mapping points, the second central point and the third central mapping point;
• and
• multiplying a maximum acute angle of the angles by 2 to obtain the scaling angle.

A linking-up photographing system, comprising:

• a first camera configured to acquire a first image;
• a second camera configured to acquire a second image presenting a FOV which partially at least overlaps a FOV of the first image;
• a calibration processor configured to establish a control look-up table according to the first image and the second image;
• and
• a control processor configured to receive a designating command which specifies a ROI in the first image, and adjust a FOV of the second camera according to the ROI and the control look-up table, so as to control the second camera to photograph a view specified by the ROI, to obtain a third image,
• wherein the ROI is circular and comprises a plurality of boundary points, the second image comprises a second central point, and when looking up the capture position parameter corresponding to the ROI in the control look-up table according to the third central mapping point, the control processor performs the following steps:
• calculating a second central mapping point of the first image corresponding to the second central point;
• calculating a third central mapping point of the second image corresponding to the third central point;
• defining a first reference circle by setting the second central mapping point to be a center of circle, and by setting a distance between the second central mapping point and the third central point to be a radius, wherein the first reference circle joins two of the boundary points;
• calculating two boundary mapping points of the second image corresponding to the two boundary points joining the first reference circle;
• calculating a scaling angle according to the two boundary mapping points, the second central point and the third central mapping point;
• and
• looking up the capture position parameter corresponding to the ROI in the control look-up table according to the third central mapping point, wherein the capture position parameter comprises a tilt coefficient and a pan coefficient;
• and
• wherein when calculating the scaling angle according to the two boundary points, the second central point and the third central mapping point, the control processor calculates a plurality of angles formed by the two boundary mapping points, the second central point and the third central mapping point, and multiplies a maximum acute angle of the angles by 2 to obtain the scaling angle.