Camera that combines the best focused parts from different exposures to an image

• US 20040080661A1
• Filed: 12/05/2003
• Published: 04/29/2004
• Est. Priority Date: 12/22/2000
• Status: Abandoned Application

• Current Assignee: Jon Kristian Hagene, Sven-Ake Afsenius
• Original Assignee: Jon Kristian Hagene, Sven-Ake Afsenius
• Inventors: Hagene, Jon Kristian, Afsenius, Sven-Ake
• Application Number:
  US10/450,913
• Publication Number:
  US 20040080661A1
• Time in Patent Office: Days
• US Class Current: 348/345
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67
• CPC Class Codes: H04N 23/671 in combination with active ranging signals, e.g. using light or sound signals emitted toward objects
• CPC Class Codes: H04N 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions

Abstract

The object of the present invention is to eliminate hitherto restrictive conditions related to photography, like when attempting to register pictures with infinite depth of field, more or less, or attempt full detail-reproduction of light and shade. This is, according to the present invention, accomplished by making several recordings with differing states of focus or exposure, the images registered being similarly subdivided into smaller image-parts and a resultant image bing produced by selecting those image-parts from each set, being most suitable. Optimal image definition of an image-part can for instance be assessed by contrast-measurement techniques or separate range-finding with a laser. An analogous optimal representation of image detail can also be achieved.

Claims

1. An electrooptical instrument having an objective lens for reproducing a scene composed of objects within a field of view at different object distances in front of said lens, a focusing device for setting said lens at various focal distances, at least one electronic image detector having an entrance plane for detection and record of image information corresponding to an image of said scene, an electronic image memory for storage of image information registered by said image detector and an image-sharpness detector, characterized by:

a/ The focusing device being arranged for simultaneous and/or time-sequential focusing of said instument at different object distances,

b/ the image detection being arranged in such a way that image information, corresponding to at least two differently-focused images, i.e. with differing states of focus, is recorded and

c/ means being assigned for having said image-sharpness detector geometrically and similarly subdivide said images into image parts or sub-images corresponding to each other in such a way that there are similar sub-images, from respective differently-focused images, depicting a similar part of said scene being reproduced and

d/ means being arranged for having said image-sharpness detector directly or indirectly, and from each set of said corresponding differently-focused sub-images, select and forward to image memory, that sub-image information contributing to optimal image resolution, and merge said select image information from corresponding image parts into a final image having better image resolution than each individually focused image record by itself.

2. An instrument of claim 1 characterized by means for measuring ranges with a range-finder, to parts of the scene in front of the objective lens.

3. An instrument of claim 2 characterized by a focal distance-sensor being part of the range-finder, and where said sensor is interacting with said image-sharpness detector in order to register those ranges for each part of the field of view, giving optimal image definition.

4. An instrument of claim 1 characterized by means being included with said image-sharpness detector, for detection of light intensity differences in-between adjacent zones of pixel detectors, located in each multiple of said sub-fields of view.

5. An instrument of claim 3 characterized by means for range-adjustnent registration, viz. related to said objective lens, and means for saving in memory such object distances recorded, giving optimal image resolution for each image part subdivided, and this resulting in a three-dimensional record of a scene in front of said lens.

6. An instrument of any previous claim characterized by the said image-detector device having several parts, and they each record images being projected by said objective lens, i.e. depictions of the same scene, albeit differing as regards focusing.

7. An instrument of claim 1 characterized by means being arranged for measurement of image contrast at each of said differently-focused sub-images and means being assigned for selecting and forwarding image information from such sub-images showing optimal contrast.

8. An electrooptical instrument or camera of claim 1 and said scene being illuminated with adjustable amounts of light by an artificial source of light, characterized by means being assigned for control and variation of said illumination in such a way that each image registration of said scene is subject to an illumination-intensity level, aiming at optimal exposure for that object distance linked to the state of focus, associated with said registration.

9. An electrooptical instrument of claim 1, characterized by means being arranged for production of a depth of field-improved template image, from said differently-focused images, this template being subdivided into image-parts or sub-images, like for said differently-focused images, and means being arranged for having the image-sharpness detector measure a similarity in-between each of said corresponding differently-focused image parts on one hand and the template-image equivalent part on the other, then select and forward image information from such sub-images being most similar to the corresponding template sub-images, and merge this select image information, originating from each set of differently-focused sub-images, into a final image with better resolution than each individually focused image record by itself.

10. An instrument of claim 1 characterized by means being assigned for repeating said subdivision of differently-focused images once or several times, however each time with differing subdivision and/or differing size/shape of said image parts or sub-images, so that different resultant images are generated from one and the same scene depicted, and that a compound average-image of sorts is created, preferably by means of a pixel by pixel fusion/superposition of said resultant images.

15. An electrooptical instrument or camera of claim 13 characterized by further means being arranged for performing an image processing of whichever claim 1-12 and 17, creating depth of field-improved final images.

11. An electrooptical instrument with objective lens for reproducing a scene composed of objects within the field of view at different object distances in front of said lens, a focusing device for setting said lens at various focal distances, at least one electronic image detector with entrance plane for detection and record of image information corresponding to an image, i.e. the scene depicted, an electronic image memory for storage of image information registered by said image detector, an image-sharpness detector and an image-discriminatory device, characterized by:

a/ the said image-discriminatory device being arranged in order to enable a pre-selection of one or several priority-images,

b/ the focusing device being arranged for simultaneous and/or time-sequential focusing of said instrument at different object distances,

c/ the image detection being arranged in such a way that image information, corresponding to at least two differently-focused images, i.e. with differing states of focus, is recorded,

d/ means being assigned for having said image-sharpness detector geometrically and similarly subdivide said images into image parts or sub-images corresponding to each other in such a way that associated sub-images, from respective differently-focused images, depict the similar part of said scene being reproduced and

e/ means being arranged for having said image-sharpness detector, directly or indirectly from each set of said corresponding differently-focused sub-images, select and forward such image information, contributing to optimal image resolution in the first place and belonging to said priority-images selected in the second place and

f/ means being assigned for having the image-sharpness detector, directly or indirectly from said set of image parts, except for those parts already chosen/forwarded from step e/, select and forward other sub-image information contributing to inferior image definition and

g/ means for optional image defocusing being arranged, enabling possible further image definition degradation of said select image information from step f/, and

h/ means being arranged for assembling said image information from steps e/, f/ and optionally g/ to a final image having inferior depth of field-properfies than each individually-focused image record by itself.

12. An instrument of claim 11 characterized by said image parts from step f/ being exchanged for corresponding image-parts from another image.

13. An electrooptical instrument or camera with objective lens for reproducing a scene composed of field of view-objects in front of said lens, an adjustable exposure device for setting the state of exposure, as defined by exposure time, relative aperture and sensor sensitivity in various combinations, and at least one electronic image detector with entrance plane for image detection, viz. image-information corresponding to said scene being recorded, and an exposure meter, characterized by:

a/ means for subdivision of images recorded and of associated detector plane, into patterns of sub-images viz. corresponding sensor-parts and

b/ means for having said exposure meter measure and register, for each said sub-sensor area, the light intensity projected by said objective lens, thus enabling estimates about which states of exposure are generating the most optimal light projection on each individual sensor-part and

c/ means for exposing each of said sub-images, thereby registering each part individually, under a state of optimal exposure more or less according to step b/ decisions for each image part and

d/ means for performing electronic image processing including restoration of originally projected light levels on respective sensor-parts and, if applicable, limited capacity of memory- and/or presentation media necessitating further adjustments.

14. An electrooptical instrument or camera of claim 13 characterized by an image detection with

a/ means being arranged for recording image information corresponding to at least two differently-exposed images, i.e. with differing states of exposure,

b/ means being arranged for performing said image subdivision similarly for the different images, in such a way that corresponding sub-images from each differently-exposed image, depict the similar part of said scene reproduced and

c/ means being arranged for said exposure meter to select and forward from each set of said corresponding albeit differently exposed sub-images, that sub-image information corresponding to the most optimal states of exposure, i.e. contributing to the best detail-reproduction in the process of image registration, and merge this select sub-image information from each set of corresponding sub-images into a fmal image having better image detail-reproduction than each individually exposed image record by itself.

16. An electrooptical instrument or camera of claim 13, characterized by means being arranged for an image processing where colour- and/or white-balance of said image parts or sub-images of the resultant image, are adjusted individually.

17. An electrooptical instrument or camera having an objective lens for reproducing a scene composed of field of view-objects at different object distances in front of said lens, a focusing device for setting said lens at various focal distances, at least one electronic image detector having entrance plane for detection and record as image information of the scene, viz. as a picture, and an electronic image memory for storage of image-detector information being registered, characterized by

a/ means being assigned for simultaneous and/or time-sequential focusing of said instrument at different object distances and

b/ image registration being arranged in such a way that image-information, corresponding to at least two differently-focused images, i.e. with differing states of focus, is recorded and

c/ the differently-focused images being arranged for superposition into a compound image (M) and

d/ means being arranged for defocusing said compound image (Mb), and

e/ image intensity of said (Mb) image being arranged for a pixel-by-pixel reduction, by a factor k (Mbk) and finally

f/ a pixel-by-pixel subtraction of said image (Mbk) from said compound image (M) being arranged, giving a resultant final image (S) having better image definition and depth of field-properties than each individually focused image record by itself.

18. A method for photographing a scene in front of an objective lens of a camera, recording taking place via a detector-plane and registration being executed with the camera set to a plurality of differing focal distances, characterized in that the differently registered records are zonally subdivided in a mutually similar way, so that for each zone is arising a plurality of sub-images corresponding to said plurality of focal adjustments, and in that a final image is assembled by means of selecting that sub-image from the sub-images in each zone, showing the best image definition.

19. The method of claim 18 characterized in that said recordings are executed in one context while said subdivision into sub-images and assembly of the same sub-images is taking place in another context and at another place.

20. The method of claim 18 characterized by a registration-procedure where a firstly-registered image record is transferred to an image-memory, and a subsequent recording is compared sub-image by sub-image to the one present in the image memory, whereby that sub-image of the two having the better image definition, is selected, being retained in the image memory, and said method-steps being iterated for subsequent images recorded, so that the resulting final image ends up in said image memory.

21. An electrooptical instrument or camera having a depth of field-modifying function, with objective lens for depicting a scene composed of field of view-objects at various object distances in front of said objective lens, and having a focusing device for setting said objective lens and having an image-registration device, characterized by:

a/ said focusing device being arranged for focusing the instrument at differing object distances,

b/ said image detection being arranged in such a way that image information, equivalent to at least two differently-focused images, i.e. having differing states of focus, is recorded and

c/ means being assigned for using differing states of magnification when performing image registration and/or processing of said differently-focused images.