Image generation apparatus, image generation system and image synthesis method

• US 20050220361A1
• Filed: 03/23/2005
• Published: 10/06/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamasaki, Masami
• Granted Patent: US 7,412,112 B2
• Time in Patent Office: Days
• US Class Current: 382/284
• CPC Class Codes: G06V 10/16 using multiple overlapping images; Image stitching
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 20/54 of traffic, e.g. cars on the road, trains or boats

Abstract

A surveillance system includes an image deformation unit for deforming the image captured or picked up by a surveillance camera so that the appearance of a specified region within this image has the same geometric shape as that of its corresponding region on the map, and an image synthesis display unit operable to extract the specific region of the deformed image and synthesize it in the corresponding map region for on-screen visualization, obtaining the mutual relationship of a plurality of images.

Claims

1. An image generation apparatus connected to a plurality of imaging devices for acquiring images from different directions, said apparatus comprising:

a unit receiving from said imaging devices image data indicative of respective images as taken thereby;

an extraction unit extracting a specified region in units of said image data; and

a synthesis unit combining said extracted image with map information containing an imaging area of said imaging device to thereby generate an image.

2. The image generation apparatus according to claim 1, further comprising:

a unit retaining the map information containing the imaging area of said imaging device; and

a conversion unit converting a geometric shape of said image based on said map information, wherein

said extraction unit extracts a specified region of said image data thus converted.

3. The image generation apparatus according to claim 2, wherein said conversion unit performs conversion for causing the specified region extracted at said extraction unit to be identical in geometric relationship to said map information.

4. The image generation apparatus according to claim 3, wherein said conversion unit performs conversion per said imaging device based on a parameter indicative of correlation between a first position coordinate included in said specified region of the image to be taken and a position coordinate of said map information corresponding to said first position coordinate.

5. The image generation apparatus according to claim 2, wherein said extraction unit extracts from said image data converted by said conversion unit a region in which said image data and said map information are identical in geometric relationship to each other.

6. The image generation apparatus according to claim 5, wherein the apparatus retains in advance mask information per said imaging device for indicating a region in which the image data converted by said conversion unit is identical in geometric relationship to said map information, and wherein said extraction unit extracts, based said mask information per said imaging device, a specified region from said image as taken by each said imaging device.

7. The image generation apparatus according to claim 2, further comprising:

a display unit displaying on a display screen the image synthesized by said synthesis unit.

8. An image display apparatus being connected to a plurality of imaging devices for taking images from different directions and having a display unit for displaying map information containing an imaging area of more than one of said imaging devices, said apparatus comprising:

a conversion unit converting an image acquired by each said imaging device in such a way that a portion of the image is identical in geometric relationship to a partial region of said map information, wherein

said display unit displays an image of a region out of the image converted by said conversion unit which is identical in geometric relationship to said map information in a display region for displaying said map information in accordance with said geometric relationship.

9. An image synthesis method for combining together images to be taken by a plurality of imaging devices, said method comprising the steps of:

retaining map information containing an imaging area;

acquiring said images;

converting each said image based on a parameter correlated per said camera device in such a manner that a partial region of said image is identical in geometric shape to a specified region of said map information;

extracting from the converted image an image of a region which is identical in geometric shape to the specified region of said map information; and

combining together the extracted image and said map information.

10. An image generation system having a plurality of camera devices and an image generation apparatus connected to respective ones of said camera devices via a network, wherein

each said camera device has an imaging unit for image acquisition and a unit for sending the image thus acquired to said image generation apparatus,

said image generation apparatus comprises:

a storage unit retaining in advance map information containing an imaging area;

a unit receiving said image;

a unit converting said image based on a parameter correlated per said camera device in such a manner that a partial region of said image is identical in geometric shape to a specified region of said map information;

an extraction unit extracting from the converted image an image of a region identical in geometric shape to the specified region of said map information;

a unit synthesizing the extracted image and said map information to thereby generate an image; and

a display unit displaying the synthesized image.

11. The image generation system according to claim 10, wherein said camera device has a synchronous reference counter, for sending and receiving, between camera devices, synchronization information concerning a synchronization signal for use as a reference of imaging timing, for adjusting based on said synchronization information a readout value of said synchronous reference counter, for generating a synchronization signal based on the readout value of said synchronous reference counter, and for controlling said camera devices based on said synchronization signal.

12. The image generation system according to claim 11, wherein said camera device has a frame number generator for uniquely calculating a frame number from the readout value of said synchronous reference counter, the frame number generated by said frame number generator being buried in units of acquired images, and wherein

said image generation apparatus synthesizes, based on the frame number being buried in an image to be received from each said camera device, an image with its frame number being identical thereto and said map information.