JP3981557B2 - Image recording / playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recording / reproducing apparatus, and more particularly to correction of misalignment between a visual field area and an actual recording area.
[0002]
[Prior art]
In recent years, with the development of PCs, in an electronic camera such as a digital camera as an image input means, an image display monitor unit such as a liquid crystal is provided on the back of the camera, and a preview image before photographing or a photographed image is displayed on the monitor. There are things that can be displayed in the section. The general operation procedure is that the user decides the position of the subject while taking a picture while looking at the monitor unit. In addition to the monitor unit, there is a case where the subject is checked by looking through the optical viewfinder and the subject in the viewfinder is photographed. However, both the case of shooting by the monitor unit and the case of shooting by the viewfinder do not always match the actually recorded image. In particular, in the case of shooting with an optical viewfinder at a short distance, a so-called parallax phenomenon occurs in which a large shift occurs between the image area in the viewfinder and the actual recording area.
Japanese Patent Application Laid-Open No. 5-64045 discloses a camera with a printer capable of economically recording images of a plurality of types of screen sizes and a recording medium cartridge thereof. According to this, cartridges that are detachably loaded in a camera with a printer are prepared for various image recording media having different screen sizes. The width of the base paper carrying the image recording medium is constant regardless of the screen size. In the field of view of the camera viewfinder, a plurality of field display frames A, B, and C corresponding to their screen sizes are formed. An identification display corresponding to the size of the recording medium unique to the cartridge is formed on the cartridge, and the camera automatically identifies the screen size based on the identification display.
[0003]
[Problems to be solved by the invention]
Since conventional digital cameras do not have means for correcting the parallax phenomenon, the subject confirmed with the finder and the actual recorded image do not match, and the true function of the finder has not been achieved. Japanese Patent Laid-Open No. 5-64045 discloses an invention in which an image to be recorded on a printer is automatically identified and matched by an identification display so as to match the image size of the finder, thereby eliminating the waste of recording paper. The invention differs from the invention in which the parallax phenomenon is corrected by a correction method in its configuration and means.
In view of such problems, an object of the present invention is to provide an image recording / reproducing apparatus that automatically corrects a deviation amount between a visual field area and an actual recording area and always matches the visual field area with the actual recording area.
[0007]
[Means for Solving the Problems]
For the present invention to solve the above problems, claim 1 includes an imaging means for outputting an image data by imaging an object, an image data encoding means for encoding the image data, encoded the image Image recording means for recording data, first image area confirmation means for confirming an image area to be photographed based on image data output by the imaging means , and a second image for optically confirming the image area to be photographed In the image recording / reproducing apparatus comprising the region confirmation unit, the first image region confirmation unit includes a deviation amount between the image region confirmation unit and the actual image actually taken by a predetermined deviation amount. And the second image region confirmation unit corrects the amount of deviation between the image region confirmation unit and the actual image actually captured based on the distance information to the subject and the zoom position information. It is characterized by that.
As the image area confirmation means, there are a method for confirming by displaying an object on an image display device such as an LCD, and a method for confirming by looking through the object with an optical finder. In the former case, the amount of deviation between the visual field area and the actual recording area is a substantially constant amount. Therefore, a predetermined amount of deviation is set in advance, and when the image display device is selected, the amount is corrected by that amount. In the latter case, the amount of displacement differs depending on the distance to the subject and the zoom position, and the amount of displacement varies depending on the horizontal and vertical directions. Therefore, the amount of displacement is corrected by calculating the distance information and zoom position information each time. There is a need to.
According to this invention, in the image display device that displays the image area captured by the image area confirmation unit, the amount of deviation between the image region confirmation unit and the actual image actually captured by a predetermined amount of deviation set in advance. In the case of an optical viewfinder in which the image area confirmed by the image area confirming means is confirmed by a finder, the image area confirming means and the actual image actually captured are based on the distance information to the subject and the zoom position information. Since the shift amount is corrected, it is possible to correct the shift amount optimal for the image area confirmation unit.
Claim 2, the deviation amount corresponding to the distance information and zoom position information to the subject is an effective means of the invention to have been recorded in the respective separate table with respect to the horizontal direction and the vertical direction of the object is there.
The relationship between the distance information to the subject and the shift amount changes in a linear function with the zoom position as a parameter. And it is recorded on the table individually for the horizontal direction and the vertical direction of the subject. Therefore, if the distance of the subject is known, the amount of deviation is uniquely detected. According to such technical means, the shift amounts corresponding to the distance information to the subject and the zoom position information are recorded in separate tables with respect to the horizontal direction and the vertical direction of the subject, respectively. The amount can be corrected.
[0008]
According to a third aspect of the present invention, it is an effective means of the present invention to acquire distance information to the subject from autofocus information.
If the distance of the subject is known, the amount of deviation is uniquely detected. Therefore, the simplest method for obtaining the distance information is most surely to use autofocus, which is generalized as a known technique, for the camera. According to such technical means, since the distance information to the subject is obtained from the autofocus information, the amount of deviation can be calculated at the lowest cost without requiring any special means.
According to a fourth aspect of the present invention, the amount of deviation set in each of the image display device and the optical viewfinder is recorded in the header area of an image file composed of a header area and an image data area. Means.
The shift amount of the actual image area by the image display device is always constant. Therefore, when an image display device is selected, a certain amount of deviation is recorded. In addition, when the optical finder is selected, the amount of deviation varies depending on the zoom amount and the distance from the subject, and therefore computation is necessary. For this reason, the computation result is recorded in the header area of the image data area. . According to this technical means, the shift amount set in each of the image display device and the optical viewfinder is recorded in the header area of the image file composed of the header area and the image data area, and therefore, the image and the shift amount are recorded. The quantity contrast can be clarified.
According to a fifth aspect of the present invention, a shift amount display unit that displays the shift amount individually in units of pixels with respect to the horizontal direction and the vertical direction of the subject, and correction based on the shift amount displayed on the shift amount display unit is provided. It is also an effective means of the present invention that it is possible to select whether or not to perform processing.
The display device displays the amount of misalignment in addition to the image to clarify how much the misalignment is with respect to the actual image area, so that unnecessary processing is not performed for the misalignment amount that does not require correction. Alternatively, when it is desired to deliberately shift and obtain a shooting effect, it is preferable to select whether or not to perform correction processing. According to this technical means, it is possible to select whether or not to perform the correction process based on the deviation amount displayed on the deviation amount display means, so that it is possible to widen the variation of photographing.
According to a sixth aspect of the present invention, when the image recorded on the image recording means is reproduced on the image display device, it is also provided with a reduced display means for reducing the reproduced image to an arbitrary magnification for reproduction. Means.
When a conventional electronic camera plays a presentation file created on a personal computer or the like and outputs it to a normal TV, the image may be out of the effective display area of the display device. In such a case, if the image reproduced by the image display device can be reduced, it is possible to prevent the effective display area from being removed. According to this technical means, when the image recorded in the image recording means is reproduced on the image display device, the reduced image display means for reducing the reproduced image to an arbitrary magnification for reproduction is provided. It is possible to prevent out of the area.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a block diagram of a digital camera according to an embodiment of the present invention. In this configuration, a lens 1 that collects an optical image of a subject, a diaphragm unit 2 that focuses a light beam collected by the lens 1, and a plurality of lenses (not shown) are moved and focused, or the diaphragm unit 2 is A motor driver 11 to be driven, a CCD (Charge Coupled Device) 3 that photoelectrically converts an optical image that has passed through the lens 1 and the diaphragm 2, and a CDS (Correlated Double Sampling) 4 that reduces noise contained in the CCD 3. An A / D converter 5 that converts an analog signal from the CCD 3 into a digital signal, a timing generator 13 that generates the timing of the CCD 3, the CDS 4, and the A / D converter 5, and image processing according to image processing parameters. Imaging by a digital signal processing circuit 7 to be performed, a frame memory 6 for storing a recorded image of an imaging pixel and an image processed image, and a liquid crystal display (LCD) An image display unit 8 for displaying an image, an image compression / expansion circuit 9 for compressing or expanding image data processed by the digital signal processing circuit 7 into original image data, and image data compressed by the image compression / expansion circuit 9 are stored. The memory card 10 that performs the predetermined control based on the control program, the operation unit 17 having a release button for the operator to operate the camera body, and the number of films and the flashing state of the strobe are monitored. Mode display unit 15, strobe 12 that illuminates the subject, AF sensor 16 for autofocus, DC-DC converter 19 that converts the voltage of the battery 18, and transmission that transmits the captured image to an external PC or the like Unit 20, a card I / F 21 for interfacing the frame memory 6 and the memory card 10, and an optical fan for confirming the subject. It is composed of an indah 22.
[0010]
Next, an outline of the operation of the digital still camera 100 having this configuration will be described with reference to FIG. When the operator looks into the subject from the optical viewfinder 22 or the image display unit 8 and presses the release button of the operation unit 17, the CPU 14 detects the signal and drives the lens 1 and the diaphragm 2 to the motor driver 11. The subject image is focused on the CCD 3. If necessary, the strobe 12 is caused to emit light. A series of these operations is automatically performed by the CPU 14 based on information from the AF sensor 16 and the like. The image focused on the CCD 3 is sequentially taken out by the clock generated from the timing generator 13, and the noise contained in the data is reduced by the CDS 4. Here, the reset noise is dominant as the noise included in the output signal of the CCD 3. In order to reduce this noise, the reset noise is canceled by subtracting both from the video signal included in the signal period, the reset noise, and the reset noise included only in the field-through period. The analog signal is converted into a 10-bit digital signal by the A / D converter 5, input to the digital signal processing circuit 7, and temporarily stored in the frame memory 6. Then, the data temporarily stored in the frame memory 6 is processed according to an instruction from the CPU 14 according to the parameter, and the processed image is stored in the frame memory 6 again. Further, the data written in the frame memory 6 is sent to the image display unit 8 to display the contents. The frame memory 6 is an image memory that can store image data of at least one screen of the imaging pixels. For example, a video random access memory (VRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM). ) Or a commonly used memory such as SDRAM (Synchronous DRAM).
[0011]
Here, if the operator wants to record the image on the memory card 10 according to the intention of the operator, the CPU 14 instructs the digital signal processing circuit 7 to store the image on the memory card 10 according to the instruction from the operation unit 17. Execute the control to transfer. That is, the image-processed image is read from the frame memory 6 and sent to the image compression / expansion circuit 9. Here, the image is compressed by the JPEG (Joint Photographic Experts Group) method and stored in the memory card 10. As this encoding algorithm, ADCT (adaptive discrete cosine) is used, and a hierarchical encoding in which an image with a low resolution is first encoded and gradually becomes higher is also adopted. Thus, the memory card is for compressing the data stored in the frame memory 6 and storing the compressed data. In addition to this, for example, it may be configured to record in an internal memory of about 8 MB or a smart media / compact flash.
Conversely, when displaying the contents of the memory card 10 on the image display unit 8 or when connecting the image data to another PC via the transmission unit 20, the desired memory card is inserted into the card I / F 21. When instructed from the operation unit 17, the CPU 14 instructs the digital signal processing circuit 7 to read the compressed image data of the memory card, inputs it to the image compression / decompression circuit 9, and decompresses the data according to the compression algorithm. The image is returned to the original and the image is displayed on the image display unit 8.
[0012]
FIG. 2 is a diagram for explaining the amount of deviation according to the first embodiment of the present invention. This shows an area (hereinafter referred to as a viewfinder visual field area) 25 that can be seen with an optical finder and an area (hereinafter referred to as an actual recording area) 26 that is actually photographed. The internal area is the finder visual field 25, and the actual recording area 26 is set so as to cover this. Therefore, a shift area 27 exists around the viewfinder visual field area 25. When the finder means is an image display device such as an LCD, the digital image processing circuit 7 performs processing so that the entire image area to be recorded is displayed in the effective display area of the image display device. When the finder means is an optical finder, the actual recording area 26 is set to be larger than the finder visual field area 25, but the area actually recorded in the memory is the finder visual field area 25. Since there is no need to record in the memory, only the finder field area 25 is recorded.
Thus, in order to detect that the finder means is an optical finder, when the LCD display is set to OFF, the user determines that the optical finder is being used. Alternatively, an infrared sensor may be installed near the optical viewfinder, and a case where the distance of the subject approaches a predetermined distance or less may be detected and automatically determined as the optical viewfinder. As another method, the shift area may be recorded as all white data or all black data.
As described above, the image recording / reproducing apparatus digitizes a subject by photoelectric conversion using an imaging device such as a CCD. The digitized image data is compressed after image processing and stored in the memory. When reproducing, the image stored in the memory is expanded and displayed on the display device. Here, as means for confirming the image of the subject, there are a case of photographing while displaying the subject image on the display device and a case of photographing while looking through another finder. In the former case, the visual field area displayed on the display unit is not necessarily an actual actual recording area, and the visual field area is generally narrower. That is, a useless shift area 27 is generated between the actual recording area 26 and the viewfinder visual field area 25. Therefore, in order to eliminate this useless area, image processing is performed so that the actual recording area 26 and the viewfinder visual field area 25 coincide. Further, in the case of the optical viewfinder, the deviation is further increased as compared with the case of the display device, and the useless area is increased. In particular, the deviation becomes more noticeable as the distance from the subject becomes shorter. Therefore, only the data of the finder visual field 25 is recorded in the memory as actual recording so as to suppress useless memory. As a result, the waste of memory can be reduced as much as possible, and the finder visual field area 25 and the actual recording area 26 can be matched.
[0013]
FIG. 3 is a diagram for explaining the amount of deviation according to the second embodiment of the present invention. 3A is a diagram showing the field of view of the optical finder when the distance to the subject is 3 m, for example, and FIG. 3B is the field of view of the optical finder when the distance to the subject is 0.3 m, for example. FIG. In the case of FIG. 3A, since the distance to the subject is relatively long, the centers A and B of the actual recording area 26 and the finder visual field area 25 coincide with each other so that the entire finder visual field area 25 can be photographed. . However, in the case of FIG. 3B, since the distance to the subject is a short distance, the centers A and B of the real recording area 26 and the finder visual field area 25 are shifted, and the entire finder visual field area 25 can be photographed. Can not. That is, the parallax occurs depending on the distance to the subject, and a large parallax occurs particularly in the proximity region. Therefore, when the x-axis shift amount between the center A of the actual recording area 26 and the center B of the viewfinder visual field area 25 is x1, and the y-axis shift amount is y1, distance information to the subject and zoom position information are obtained by a method described later. Can be measured, the shift amounts x1 and y1 can be determined. Then, if the center B of the finder visual field area 28 is calculated from the deviation amount and is corrected so that the center A of the original actual recording area 26 coincides, the deviation amount is corrected and the finder visual field area is within the actual recording area 26. 25 is included. Thereby, the image of the visual field area without a gap can be taken.
[0014]
FIG. 4 is a diagram showing an actual recorded image when characters such as a document and a white board are photographed according to the third embodiment of the present invention. FIG. 4A is a diagram of imaging data, and FIG. 4B is a diagram after binarization processing. Normally, a document document is described in black characters on a white background, and the document area is extracted using this difference to make the defective area, for example, all white. This is particularly effective in a mode for binarizing characters. Specifically, the luminance signal level average value of a certain area at the center of the document 31 in FIG. 4A is calculated, and when this value is used as a threshold value and the certain area is lower than this threshold value, for example, as shown in the figure When the background of 31 is black 30, this signal level is lower than the threshold value, so that unnecessary images in the peripheral portion can be erased by setting all white data. Further, when the data of the document 31 is a document, it is black or white data, and therefore binarization processing may be performed. FIG. 4B shows the result processed in this way. The threshold value may be set by the user.
As described above, when shooting characters written on white standard paper, since there is no halftone as data, it may be processed by binarization processing of white or black. Therefore, since the area other than the standard paper is unnecessary data, in order to remove it, first, the average brightness at the center of the standard paper is detected, and the level is lower than that level (the level with less reflection). By forcibly setting the white level, it is possible to remove unnecessary images around the standard paper. The threshold value is determined based on the average value of the luminance signal levels in a predetermined area at the center of the image area. However, depending on the situation, it may be desired to display the peripheral part. In such a case, it is preferable that the predetermined level can be set. Thereby, a peripheral part can be displayed or removed arbitrarily.
[0015]
FIG. 5 is a diagram showing an image file structure according to the fourth embodiment of the present invention. As shown in the figure, the image file 35 records the above-described information 37 on the finder visual field area and the actual recording area in a header area 36 that forms a pair with the image data area 38.
As described above, the amount of deviation of the actual image area by the image display device is always constant. Therefore, when an image display device is selected, a certain amount of deviation is recorded. In addition, when the optical finder is selected, the amount of deviation varies depending on the zoom amount and the distance from the subject, and therefore computation is necessary. For this reason, the computation result is recorded in the header area of the image data area. . Thereby, the contrast between the image and the shift amount can be clarified.
FIG. 6 is a flowchart for setting the amount of deviation between the visual field area and the actual recording area according to the fifth embodiment of the present invention. First, it is checked whether the image display unit is used as a finder (S1). For example, when the LCD is used (YES route), deviation information determined at the circuit design stage is set in the image file (S2). When the optical finder is used in step S1 (NO route), distance information and zoom position information are acquired (S3), and the amount of deviation is calculated from the information and set in the image file (S4).
As described above, the image area confirmation means includes a method of displaying and confirming a subject on an image display device such as an LCD, and a method of confirming by looking through the subject using an optical viewfinder. In the former case, the amount of deviation between the visual field area and the actual recording area is a substantially constant amount. Therefore, a predetermined amount of deviation is set in advance, and when the image display device is selected, the amount is corrected by that amount. In the latter case, the amount of displacement differs depending on the distance to the subject and the zoom position, and the amount of displacement varies depending on the horizontal and vertical directions. Therefore, the amount of displacement is corrected by calculating the distance information and zoom position information each time. There is a need to. As a result, it is possible to correct the shift amount optimum for the image area confirmation means.
[0016]
FIG. 7 is a diagram illustrating the relationship between the distance to the subject and the amount of deviation, where (a) is a diagram in the horizontal direction and (b) is a diagram in the vertical direction. For example, in the horizontal direction, the amount of deviation of the intersection point P1 from the zoom position straight line 40 at the distance d is m, and in the same vertical direction, the amount of deviation from the intersection point P2 from the zoom position straight line 42 at the distance d. The amount is n. Therefore, by making these associated values into a table, the amount of deviation can be easily calculated from the distance. As the zoom position information, AF sensor output information used for autofocus can be used.
As described above, the relationship between the distance information to the subject and the shift amount changes in a linear function with the zoom position as a parameter. And it is recorded on the table individually for the horizontal direction and the vertical direction of the subject. Accordingly, since the amount of deviation is uniquely detected if the distance of the subject is known, the amount of deviation can be corrected with a simple calculation.
FIG. 8 is a view showing the amount of deviation according to the sixth embodiment of the present invention. This is because the horizontal and vertical shift amounts 46 are displayed on the display unit 45 in units of pixels, and a character 47 “Do you want to execute correction processing?” Is displayed below it. If not, “NO” 49 is a touch panel type display unit. Here, when the user instructs the correction process, a process of moving the LCD image display position by the shift amount from the shift information is performed.
In this way, the display device displays the amount of misalignment in addition to the image to clarify how much the misalignment is with respect to the actual image area, and performs unnecessary processing for the misalignment amount that does not require correction. When it is desired not to make a shooting effect, or to deliberately shift the shooting effect, it is preferable to select whether or not to perform correction processing. Thereby, the variation of photography can be expanded.
Further, when a presentation file created on a personal computer or the like is played back on a conventional electronic camera and output to a normal TV, the image may be out of the effective display area of the display device. In such a case, if the image reproduced by the image display device can be reduced, it is possible to prevent the effective display area from being removed.
[0018]
【The invention's effect】
According to the present invention as described above, the first aspect, when the image area confirmation means is the image display apparatus for displaying an image area to be photographed, and the image area checking unit by a predetermined shift amount set in advance In the case of an optical viewfinder that corrects a deviation amount from an actual image that is actually captured and confirms an image area that is captured by the image area confirmation unit using a finder, the image region confirmation unit is based on distance information to the subject and zoom position information. Since the amount of deviation between the actual captured image and the actual image is corrected, it is possible to correct the amount of deviation optimum for the image area confirmation means.
According to the second aspect of the present invention, since the shift amounts corresponding to the distance information to the subject and the zoom position information are recorded in separate tables for the horizontal direction and the vertical direction of the subject, the shift amount can be obtained by simple calculation. Can be corrected.
According to the third aspect of the present invention, since the distance information to the subject is acquired from the autofocus information, no special means is required, and the shift amount can be calculated at the lowest cost.
According to a fourth aspect of the present invention, the shift amount set in each of the image display device and the optical viewfinder is recorded in the header area of an image file composed of a header area and an image data area. The contrast of can be clarified.
According to the fifth aspect of the present invention, it is possible to select whether or not to perform the correction process based on the shift amount displayed on the shift amount display means.
The sixth aspect, when reproducing the image recorded on the image recording unit in the image display apparatus, since with a reduced display means for reproducing by reducing the regeneration picture to a desired magnification, the effective display region Can be prevented from coming off.
[Brief description of the drawings]
FIG. 1 is a block diagram of a digital camera according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a deviation amount according to the first embodiment of the present invention.
FIGS. 3A and 3B are diagrams for explaining a deviation amount according to the second embodiment of the present invention, and FIG. 3A is a view showing a field of view of an optical viewfinder when a distance from a subject is 3 m, for example; ) Is a diagram showing the field of view of the optical viewfinder when the distance to the subject is 0.3 m, for example.
FIGS. 4A and 4B are diagrams showing actual recorded images when a character such as a document or a white board is photographed according to the third embodiment of the present invention, FIG. FIG.
FIG. 5 is a diagram showing an image file structure according to a fourth embodiment of the present invention.
FIG. 6 is a flowchart for setting a shift amount between a visual field area and an actual recording area according to a fifth embodiment of the present invention.
7A and 7B are diagrams illustrating a relationship between a distance to a subject and a shift amount according to the present invention, in which FIG. 7A is a diagram in the horizontal direction, and FIG. 7B is a diagram in the vertical direction.
FIG. 8 is a diagram showing a deviation amount according to a sixth embodiment of the present invention.
[Explanation of symbols]
7 Digital signal processing unit, 8 Image display unit, 14 CPU, 16 AF sensor 22 Optical viewfinder

Claims (6)

Imaging means for imaging a subject and outputting image data;
Image data encoding means for encoding the image data;
Image recording means for recording the encoded image data;
First image area confirmation means for confirming an image area to be photographed based on image data output by the imaging means ;
Second image area confirmation means for optically confirming an image area to be photographed;
In an image recording / reproducing apparatus comprising:
In the first image area confirmation means, a deviation amount between the image area confirmation means and the actual image actually taken is corrected by a predetermined deviation amount set in advance, and in the second image area confirmation means, An image recording / reproducing apparatus that corrects a deviation amount between the image area confirmation unit and the actual image that is actually captured based on distance information to the subject and zoom position information. 2. The image recording / reproducing according to claim 1 , wherein a shift amount corresponding to the distance information to the subject and the zoom position information is recorded in a separate table for each of the horizontal direction and the vertical direction of the subject. apparatus. The image recording / reproducing apparatus according to claim 2 , wherein distance information to the subject is acquired from autofocus information. 2. The image according to claim 1 , wherein the shift amount set by each of the image display device and the optical viewfinder is recorded in the header area of an image file including a header area and an image data area. Recording / playback device. Whether or not to perform a correction process based on the deviation amount displayed on the deviation amount display means, comprising a deviation amount display means for individually displaying the deviation amount in units of pixels with respect to the horizontal direction and the vertical direction of the subject. image recording and reproducing apparatus according to any one of claims 1 to 4, characterized in that it has a selectable or. When playing the images recorded in the image recording unit in the image display apparatus, according to claim 1 to 5, characterized in that with a reduced display means for reproducing by reducing the regeneration picture to a desired magnification The image recording / reproducing apparatus according to any one of the above.

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