CN101047790A - Viewport correction pan method of wide-angle image - Google Patents

Abstract

This invention provides a method for picking up and correcting images from wide-angle static or video images, which can display said picked-up images undistortionally, and the correction method maps a section of a wide-angle image to a plane, which is an image plane watching angles. This invention can watch angles movably and repeat the pick-up and correction steps to pick up images undistornally.

Description

The viewport correction pan method of wide-angle image

Technical field

The present invention is the technology of relevant image processing, more clearly, is the view-point correction electronics pan method of relevant wide-angle image.

Background technology

Wide-angle image has non-standard resolution (for example, 1800 * 460), so when watching this wide-angle image on the display unit of desiring in standard (for example, 640 * 480), then may change display size or sacrifice resolution.Known electronics pan (e-panning) method is the acquisition wide-angle image, and only shows and this acquisition fragment (slices) of image afterwards wherein there is no any correction program.Yet, because wide-angle image is to be presented on a periphery or the spherical surface, so known electronics pan method can produce the result of distortion.

Pan (panning) technology often is applied to the monitor camera, and for example, United States Patent (USP) 6977678 is to describe to utilize the purpose of motor pan method with the supervision of reaching different directions.This kind method needs entity moving-member (that is, motor), therefore easily produces the problem of mechanical aging and higher power dissipation (needing CD-ROM drive motor) is arranged.In addition, mechanical component also increases the cost and the space requirement of system.

Summary of the invention

Because the problems referred to above, one of the present invention purpose provides a kind of view-point correction method that is able to show the fragment of wide-angle (or panorama) image undistortedly.Another object of the present invention provides a kind of electronics viewport correction pan method that is replaced motor.The disclosed method of the present invention has low cost, space requirement is little and advantage such as low power consumption.

According to one of the present invention form, a kind of view-point correction method of wide-angle image comprises: wide-angle static image or wide-angle video image (a) are provided; (b) determine image capture point; (c) according to this image capture point to capture one of this wide-angle image fragment; And (d) to this pick-up image fragment execution view-point correction program.

According to another form of the present invention, a kind of viewport correction pan method of wide-angle image comprises: wide-angle static image or wide-angle video image (a) are provided; (b) determine the starting point of a pick-up image; (c) according to this starting point to capture one of this wide-angle image fragment; (d) this pick-up image fragment is carried out the view-point correction program; (e) this fragment image after pruning and demonstration are proofreaied and correct; And (f) increase progressively a little displacement and become the starting point of next pick-up image to this starting point and repeat above-mentioned steps (c), (d) and (e).

Technical scheme by invention provides following technique effect.Wide-angle image has unavoidable fish-eye shaped distortion in essence.Wide-angle image has big resolution usually and its resolution not necessarily has the geometric ratio relation with the general resolution of specification that shows, and can't suitably be presented on the general display unit.Therefore, for the purpose of watching, need the part that reduces the resolution of wide-angle image or only show wide-angle image usually.The present invention discloses a kind of bearing calibration and shows the viewpoint that it is the most natural with the fragment with wide-angle image undistortedly.The present invention also allows contains the pan function that does not need motor, thereby the solution of expensive benefit of a wide area pan camera system and power saving is provided.

Description of drawings

Fig. 1 is the flow process of proofreading and correct the pan method according to viewpoint of the present invention (perspective).

Fig. 2 shows by three obtained image planes of the camera of three different directions.

Fig. 3 is the vertical view of Fig. 2 of corresponding periphery.

Fig. 4 (A) and (B) be view-point correction schematic diagram according to one of the present invention embodiment.

Fig. 5 shows the embodiment according to one of the present invention, with the fragment image of the wide-angle image of simulation pan effect.

Embodiment

Fig. 1 is a summary of describing viewport correction pan method.The method is to obtain a section and carry out view-point correction from wide-angle image.It is processed for demonstration to proofread and correct the back image at last.

As shown in Figure 1, at first with wide-angle image input, this image input can be from obtained image of single wide-angle lens camera system or the image that is made of via map interlinking many photographic systems.In addition, this wide-angle image can be static image or is video image.Then import an initial position one of to be used as in this wide-angle image the starting point of pick-up image.According to this starting point, capture one of this wide-angle image fragment.At this fragment image, carry out a view-point correction program (will be specified in the back) to produce a undistorted fragment image.Again this fragment image after view-point correction is carried out and pruned (cropping), then just the image of handling can be shown on the display unit to remove the white space in the image.Next, increase progressively a little displacement to the starting point of this pick-up image and repeat steps such as follow-up image capture, view-point correction, pruning and demonstration.The above-mentioned step that increases progressively displacement can be reached the pan camera system that is equivalent to known techniques and utilize motor progressively to rotate the effect of camera.Therefore, can successfully simulate one have pan function camera system and need not entity moving-member (motor).

Because it is wide-angle image is to be presented on a periphery or the spherical surface,, especially more obvious in the both sides of this fragment image so the fragment image that directly captures from wide-angle image will have the phenomenon of distortion or distortion.At this problem of dtmf distortion DTMF, this case inventor proposes the solution of a kind of being called " view-point correction ".Below be so that an embodiment of view-point correction method of the present invention to be described referring to figs. 2 to Fig. 5.For making summary of the invention be easy to understand, the following description is to be example with the periphery.

At first, with reference to figure 2 and Fig. 3 so that a kind of formation method of wide-angle image to be described.Fig. 2 shows by obtained three image planes (P1, P2, P3) of the camera of three different directions (D1, D2, D3).The vertical view of Fig. 3 displayed map 2, dotted line are wherein represented a periphery C.These three image planes (P1, P2, P3) are through being converted to cylinder coordinate, map interlinking and other and handling the back and shape one one of is presented on this periphery C wide-angle image.

Next, capture a fragment image from the assigned address that is presented on the wide-angle image on this periphery C.This assigned address is the viewing angle that is directly related to the starting point of pick-up image and will influences the gained image.

Known electronics pan (e-panning) method only directly is shown in above-mentioned fragment image not have on the display unit and further handles, and it is to be equivalent to a certain section of periphery C directly is shown on the display unit.Object in the image of gained is certain unavoidablely can distortion distortion and can't normally be presented.

Fig. 4 (A) and Fig. 4 (B) describe floor map and the schematic perspective view according to view-point correction method of the present invention respectively, and wherein C ' represents a periphery section that is captured from above-mentioned periphery C; T represents a tangent plane; F represents focal length; (x, y) picture point (pixel) on the surperficial tangent plane T; And (x _c, y _c) represent the corresponding points on the periphery.According to this embodiment of the present invention, carry out one reverse (reverse) conversion with image from face of cylinder C ' projection to tangent plane T, shown in the arrow during Fig. 4 (A) reaches (B), it is to utilize following equation:

$x_c=f*{\tan }^{-1}\left(\frac{x}{f}\right)$

$y_c=\frac{f*y}{\sqrt{x^2+f^2}}$

(x, y), its face of cylinder C ' goes up the corresponding points (x of gained for each integral point on the tangent plane T _c, y _c) will contain decimal (that is, being non-integer).Therefore, need to use secondary linear interpolation (Bi-linear Interpolation) with calculation level (x _c, y _c) on image data.In present embodiment, this image data is the color information of its picture point.Utilize aforesaid equation, to tangent plane, the method promptly is called " view-point correction " to each fragment image that is able to watch the visual angle individually from face of cylinder projection.

Fig. 5 shows image V1, V2, V3 and the V4 that absorbs from four different angles of a wide-angle image, and wherein V1 and V4 will present individually extremely near the P1 of Fig. 2 and the image of P2.After view-point correction, the execution image is pruned to remove the white space in the image of changing, and then just the image of handling can be shown on the display unit through amplification or after dwindling processing again.

Above-mentioned steps can be repeated on the starting point of other pick-up images along with increasing progressively displacement slightly, as the order of the V1 → V2 as shown in the 5 → V3 → V4 that quarrels.Therefore, utilize the shown image of view-point correction method of the present invention, with regard to the image of obtaining as the same pan function that camera system had with revolution.

Claims (11)

1. the view-point correction method of a wide-angle image comprises:

(a) provide wide-angle static image or wide-angle video image;

(b) determine image capture point;

(c) according to this image capture point to capture one of this wide-angle image fragment; And

(d) this fragment image is carried out a view-point correction program.

2. view-point correction method as claimed in claim 1, wherein this view-point correction program be image data with this fragment image from the periphery projection to the plane, produce undistorted fragment image whereby.

3. view-point correction method as claimed in claim 1, this fragment image that is wherein captured has the displaying ratio that is suitable for general display unit.

4. view-point correction method as claimed in claim 1, further be contained in the view-point correction of step (d) after, prune this fragment image in order to demonstration.

5. view-point correction method as claimed in claim 1, wherein this wide-angle static image or wide-angle video image are to be produced through map interlinking by many camera systems.

6. view-point correction method as claimed in claim 1, wherein this wide-angle static image or wide-angle video image are produced by single super wide-angle camera system.

7. the viewport correction pan method of a wide-angle image comprises:

(a) provide wide-angle static image or wide-angle video image;

(b) determine the starting point of a pick-up image;

(c) according to this starting point to capture one of this wide-angle image fragment;

(d) this fragment image is carried out a view-point correction program;

(e) this fragment image after pruning and demonstration are proofreaied and correct; And

(f) increasing progressively a little displacement becomes the starting point of next pick-up image to this starting point and repeats above-mentioned steps (c), (d) and (e).

8. viewport correction pan method as claimed in claim 7, wherein this view-point correction program be image data with this fragment image from the periphery projection to the plane, produce undistorted fragment image whereby.

9. viewport correction pan method as claimed in claim 7, this fragment image that is wherein captured has the displaying ratio that is suitable for general display unit.

10. viewport correction pan method as claimed in claim 7, wherein this wide-angle static image or wide-angle video image are to be produced through map interlinking by many camera systems.

11. viewport correction pan method as claimed in claim 7, wherein this wide-angle static image or wide-angle video image are to be produced by single super wide-angle camera system.

Images