JP4241460B2 - Electronic imaging device - Google Patents

Description

  The present invention relates to an electronic imaging apparatus capable of adjusting a focus position after image capturing.

  Japanese Patent Application Laid-Open No. 61-236841 proposes an autofocus device that allows two subjects located at different positions to perform photographing in a focused state.

  Japanese Patent Laid-Open No. 05-034573 discloses an autofocus camera having a prefocus function in which an object to be photographed is set within a focus target and a ranging operation is performed, and then the camera is redirected to a screen to be photographed and the photographing operation is performed. An improvement plan has been proposed.

  In Japanese Patent Laid-Open No. 06-086759, an axis (line of sight) in the gazing point direction observed by an observer (photographer) through a viewfinder system on an observation surface (focus plane) on which a subject image is formed by the imaging system. ) Is proposed using an eyeball reflection image obtained by illuminating the surface of the eyeball of the observer.

  In Japanese Patent Application Laid-Open No. 11-136568, when a photographer views an image on a display unit and touches and designates an intended main subject with a finger or a pen, the touch position is detected via a touch panel and a position information detection unit. Based on the touch position, the main subject on the screen is identified, exposure control (AE) is performed with emphasis on the main subject, and automatic focusing is controlled so that the main subject is in focus (AF) A digital camera has been proposed.

If there are multiple claims, please describe the purpose corresponding to each claim.
The known techniques described above are different in how to focus, but the same is true for focusing before release. In these cases, there are cases where the photographed image is not in focus at the location intended by the photographer after photographing, or where it is impossible to focus at a plurality of locations due to composition. In Japanese Patent Laid-Open No. 11-136568, it is necessary to manually indicate an area to be focused while looking at the liquid crystal screen at the time of photographing. There were problems with operability such as blurring.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to focus on a place intended by a photographer after release and determine the composition of an image, and to freely focus on a plurality of locations.

Image data storage means for storing a plurality of subject captured images from the first distance to the second distance at the time of shooting, an image display section for displaying the captured images stored in the image data storage means, and the image display section and selection means for selecting an object arbitrary above extraction means for extracting an image that can be judged that the in-focus position in each of the selected object from the image of the image data storage means, a plurality of selected on the image display unit in the subject, the synthesizing means by the extraction means synthesizes the images respectively extracted in one image, said combining means as understood synthesis history of the synthesized image by the image display unit selected locations in the selection means Display means for displaying above.

  According to claims 1 and 2 of the present invention, since the same effect as focusing on the subject after the release can be obtained, the focus position shift (out-of-focus) that can be confirmed only after shooting by the method of focusing before the release. ) Is completely absent. Further, it is possible to obtain a plurality of images with the same composition in focus at different locations.

  According to claims 3 and 4 of the present invention, it is possible to obtain an image in which a plurality of subjects are in focus. Further, since the focusing can be performed freely with a margin after the composition of the shooting is determined, a photo opportunity is not missed.

According to the fifth aspect of the present invention, since the synthesis history can be confirmed, a new image can be easily synthesized, and double synthesis at the same location can be prevented.
According to the sixth aspect of the present invention, the photographer can clearly determine the degree of focus by enlarging the selected image area.

  According to the seventh aspect of the present invention, a pan-focus image can be obtained by combining images without using a camera aperture.

(First embodiment)
A first embodiment of the invention according to the present application will be described. 1-1 and 1-2 are external perspective views of a digital camera to which the present invention is applied. FIG. 2 is a block diagram of a digital camera to which the present invention is applied. The operation up to shooting will be described based on these. When the photographer operates the main power supply 15 provided in the main body 10, the camera microcomputer 1 causes the photographing lens barrel 11 including the photographing optical system that is the imaging unit 2 and the flash 14 that is the light emitting unit 5 to protrude from the main body 10. The camera is ready for shooting. The photographer looks into the finder (eyepiece lens) 17 or operates the zoom button 18 while looking at the liquid crystal display 16 as the image display unit 6 to determine the angle of view. After the photographer determines the angle of view, when the release button 13 is operated, the photographing lens barrel 11 or at least a part of the optical system contained therein is driven to perform photographing, and a memory (not shown) that stores image data as the recording medium 7 ) Is recorded. In this embodiment, a zoom type is illustrated, but the present invention is not limited to this, and a single focus type is also applicable. The flash and viewfinder are not essential components in the present invention, and can be applied without these.

  Control from when the release button 13 is operated until image data is recorded in the memory will be described with reference to FIGS. 3-1, 3-2, and 3-3. FIG. 3-1 is a contrast graph, in which the vertical axis represents the contrast, and the horizontal axis represents the movement position along the optical axis direction of the focusing optical system. FIG. 3-2 is an enlarged view of the vicinity of step (10) in FIG. 3-1. In FIG. 3-1, when the release button 13 is operated, the camera microcomputer 1 moves the photographing lens barrel 11 or at least a part of the optical system included from the shortest focusing position (hereinafter simply referred to as the closest) to the infinite focusing position. Drive to (hereinafter simply referred to as infinity). While moving at least a part of the taking lens barrel 11 or the optical system contained therein, the image data is taken into the memory as the recording medium 7 in steps (1) to (20). That is, 20 pieces of image data are captured in the memory as shown in FIG. 3-3. In the present embodiment, 20 steps are used, but the present invention is not limited to this, and the more steps are desirable. The optical arrangement for capturing the image data into the memory is a position satisfying each region when the depth of field calculated from the allowable circle of confusion is divided from the nearest to the infinity. This will be explained using FIG. 3-2. At each step position, the front depth of field and the rear depth of field are determined from the allowable circle of confusion and the optical performance. The rear depth of field in step (9) and the front depth of field in step (10) are made continuous (9a). Further, the rear depth of field in step (10) and the front depth of field in step (11) are made continuous (10a). Then, in step (10), it is possible to obtain a photograph that is practically focused on the subject whose subject distance is (9a) to (10a). In this way, it is possible to cover all subject distances by repeating from close to infinity. In addition, you may divide | segment more finely than this. One of the 20 images obtained is displayed on the liquid crystal display 16, and the photographer selects a subject to be focused for the first time. As the selection method, a known method such as a method of pressing a touch panel type liquid crystal display or moving a cursor on the display with a jog dial or the like may be used. In order to indicate a selection area of an arbitrary size, it is desirable to surround a subject to be focused in a rectangular window. In addition, the image displayed on the liquid crystal display 16 after the release can be set in advance as to whether the image having the highest contrast average of the entire screen is automatically selected or the position of the image from the nearest to infinity is displayed.

  FIG. 4 is a diagram showing extraction of an image that is in focus best among the subjects selected by the above method. FIG. 4 is an image including a plurality of subjects at different distances, and it is assumed that A is a subject close to the subject, C is a subject close to infinity, and B is a subject at an intermediate position. As described above, since all the images from close to infinity are captured, the images in focus on the subjects A, B, and C are included in all the images. Therefore, when the photographer wants to focus on A, if A is selected by designating area x, contrast measurement unit 4 measures the contrast at the selected location, and contrast comparison unit 3 captures 20 images. In comparison, an image with the highest contrast is extracted as an in-focus image. The extracted image is an image in which A is in focus as shown in (I), and as a result, is the whole of (4) steps. Similarly, if the photographer wants to focus on B, by specifying area y and selecting subject B, (10) step image (II) will be extracted, and in case of C, (17) step ( III). If these are shown as a flowchart from when the release button is pressed until an image is extracted, it is as shown in FIG.

  In this embodiment, it is assumed that the photographing operation is performed while driving from an arrangement in which the photographing optical system is focused close to an arrangement in which the photographing optical system is focused at infinity. START is a state in which the release button 13 is operated. In step # 11, the taking lens barrel 11 or at least a part of the optical system included is driven. In step # 12, it is determined whether or not at least a part of the taking lens barrel 11 or the optical system contained therein has a predetermined optical arrangement. If it is determined that the predetermined optical arrangement is not obtained, the process returns to step # 11, and the photographing optical system is further driven. If it is determined that the predetermined optical arrangement is obtained, the subject light in the optical arrangement is taken into the memory as image data in step # 13. After the image data is captured, it is determined in step # 14 whether or not the optical arrangement is an infinite focus distance. If it is determined that the optical arrangement is not the infinite focal length, the process returns to step # 11, and images are repeatedly captured while changing the optical arrangement. If it is determined in step # 14 that the focus distance is infinity, image capture is terminated in step # 15. After completing the image capture, in step # 16, the photographer selects a subject area to be focused while looking at the liquid crystal display 16. In step # 17, the contrast of the plurality of captured image data is measured in the subject peripheral area selected by the contrast measuring unit 4, and the image having the maximum contrast is selected by the contrast comparing unit 3. As is well known, the contrast becomes higher as the image is in focus. After selecting the image with the maximum contrast, the image selected in step # 18 is recorded in the memory which is the recording medium 7. After saving the image, the camera enters standby mode (STOP).

(Second embodiment)
A second embodiment of the invention according to the present application will be described. Since the configuration of the digital camera is the same as that of the first embodiment, description thereof is omitted.

  FIG. 6 is a diagram showing the synthesis of a plurality of images extracted by the method shown in the first embodiment. FIG. 6 is an image in which subjects with different distances are in focus. By selecting three areas x, y, and z including subjects A, B, and C on the liquid crystal display 16, the most in each area. Extracts the in-focus image from all the images and combines them into a single image. The difference from the first embodiment is that when a plurality of subjects are selected at a time, images in focus at each location are extracted and automatically synthesized by a known technique. In the image, it is assumed that A is close to the subject, C is close to infinity, and B is the subject at the intermediate position, so the combined image is focused on all of A, B, and C. An image is obtained. FIG. 7 shows a series of these operations as a flowchart from when the release button is pressed until the extracted images are combined.

  In this embodiment, it is assumed that the photographing operation is performed while driving from an arrangement in which the photographing optical system is focused close to an arrangement in which the photographing optical system is focused at infinity. START is a state in which the release button 13 is operated. In step # 21, the taking lens barrel 11 or at least a part of the optical system included is driven. In step # 22, it is determined whether or not at least a part of the taking lens barrel 11 or the optical system included therein has a predetermined optical arrangement. If it is determined that the predetermined optical arrangement is not obtained, the process returns to step # 21, and the photographing optical system is further driven. If it is determined that the predetermined optical arrangement is obtained, the subject light in the optical arrangement is taken into the memory as image data in step # 23. After the image data is captured, it is determined in step # 24 whether or not the optical arrangement is an infinite focus distance. If it is determined that the optical arrangement is not the infinity in-focus distance, the process returns to step # 21 to repeatedly capture images while changing the optical arrangement. If it is determined in step # 24 that the focus distance is infinity, image capture is terminated in step # 25. After completing the image capture, the photographer selects a plurality of subjects to be focused while looking at the liquid crystal display 16 in step # 26. In step # 27, the contrast of the plurality of captured image data is measured in the object peripheral area selected by the contrast measuring unit 4, and the image having the maximum contrast is selected by the contrast comparing unit 3, respectively. As is well known, the contrast becomes higher as the image is in focus. After selecting the plurality of images having the maximum contrast, the plurality of images selected in step # 28 are processed by the data processing unit 8 and combined into one image by the data combining unit 9. If the photographer determines in step # 29 that there are more subjects to be focused, the process returns to step # 26, and the photographer selects a new subject to be focused while looking at the liquid crystal display 16, and re-enters in step # 28. Synthesize. If the photographer determines that there is no more subject to focus on, the image composition is finished in step # 29, and is recorded in the memory which is the recording medium 7 in step # 30. After saving the image, the camera enters standby mode (STOP). If only one subject is selected in step # 26, it is not necessary to synthesize, so only the image is selected in step # 27, and the contents are the same as in the first embodiment.

  In both the first embodiment and the second embodiment, after an image is recorded in the memory that is the recording medium 7, it is initially taken and it is left to the photographer to determine whether or not to delete a plurality of images. If it is not deleted, it is effective for later image correction, such as when an image in focus on another subject is obtained or when a new image is to be synthesized, but the memory capacity is used accordingly.

  In the second embodiment, the synthesized image is displayed on the liquid crystal display 16 at a location selected so as to be in focus so that the synthesis history can be understood. By doing so, it is easy to avoid synthesizing different subjects that are in focus and avoid double synthesis at the same location. In addition, since it is difficult to determine whether or not the actual image is in focus when the entire synthesized image is displayed on the liquid crystal display 16, it is possible to increase the degree of blurring in the synthesis process by enlarging the area around the selected location using a known technique. Make the distinction clear.

(Third embodiment)
FIG. 8 is a diagram showing a pan focus function that obtains an image that is all in focus using the above-described image composition. Here, as an example of an image displayed on the display, a figure in which the center subject is in focus is used. This embodiment differs greatly from the first and second embodiments in that the focusing area is set not by manual operation but by automatic operation. When shooting with the camera mode set to the pan focus mode, it is divided into, for example, 42 areas as shown in FIG. The number of divisions is not limited to this, and it is desirable that the number of divisions is large. The number of divisions may be set in advance by the photographer or may be automatically determined according to the number of images captured from close to infinity. The image with the highest contrast in one area divided from 1 to 42 is extracted from the images captured from close to infinity as shown in the second embodiment. In the case of the pan focus mode of the present embodiment, all the images in focus on the 42 areas are synthesized into one image. An image in which each area is in focus is synthesized as an image of each area portion, and an image in which all the areas are in focus is obtained as a whole. However, as the number of divisions increases, a smooth pan-focus image can be obtained. In this mode, all areas are in focus, so there is no need for manual recombination, and multiple images from the closest distance to infinity, which were the basis of composition, are stored as a combined pan-focus image. When you do, delete everything.

1-1 is a front perspective view of a digital camera to which the present invention is applied, and FIG. 1-2 is a rear perspective view of a digital camera to which the present invention is applied. Block diagram of a digital camera to which the present invention is applied Fig. 3-1 is a contrast graph, Fig. 3-2 is an enlarged view of a contrast graph, and Fig. 3-3 is a conceptual diagram of image selection. Image extraction conceptual diagram of the present invention Flowchart (extraction) of digital camera to which the present invention is applied Image extraction conceptual diagram of the present invention Flowchart (synthesis) of a digital camera to which the present invention is applied Pan focus function

Explanation of symbols

10 Camera body
11 Shooting lens barrel
12 Viewfinder objective lens
13 Release button
14 flash
15 Main power switch
16 LCD display
17 Viewfinder eyepiece
18 Zoom button
19a Mode button
19b Date button
19c Self button

Claims (8)

Image data storage means for storing a plurality of subject captured images from the first distance to the second distance at the time of shooting, an image display section for displaying the captured images stored in the image data storage means, and the image display section and selection means for selecting an object arbitrary above extraction means for extracting an image that can be judged that the in-focus position in each of the selected object from the image of the image data storage means, a plurality of selected on the image display unit in the subject, the synthesizing means by the extraction means synthesizes the images respectively extracted in one image, said combining means as understood synthesis history of the synthesized image by the image display unit selected locations in the selection means An electronic imaging apparatus comprising display means for displaying on top.   2. The electronic imaging apparatus according to claim 1, wherein the image extracted by the extracting unit is recorded in an image data storage unit.   3. The electronic imaging apparatus according to claim 1, wherein an image synthesized by the synthesizing unit is recorded in an image data storage unit.   2. The electronic imaging apparatus according to claim 1, wherein an image of the designated area is enlarged and displayed on the image display unit.   The electronic imaging apparatus according to claim 1, wherein the first distance is a shortest focusing position.   The electronic imaging apparatus according to claim 1, wherein the second distance is an infinitely focused position.   The electronic imaging apparatus according to claim 1, wherein the image that can be determined as the in-focus position is an image having the highest contrast in the designated area. The electronic imaging apparatus according to claim 1, wherein the image that can be determined as the in-focus position is an image that has the largest data size of the compressed data in the selected region.

Images