JPH06350888A - Electronic still camera - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an electronic still camera capable of outputting optimum image data in accordance with an external electronic device. [Structure] In an electronic still camera 1 for temporarily writing image data picked up by a CCD 11 into an SRAM 52, reading out the image data from the SRAM 52, and outputting the image data from each I / O port 40, 43, 45 to an external electronic device. The optimum image data is output to the external electronic device based on the format of the output image data from the electronic still camera 1 input from the external electronic device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera for outputting original image data extracted from an image pickup device to an external electronic device.

[0002]

2. Description of the Related Art Conventionally, an electronic still camera is an independent device, and image data picked up by the electronic still camera can only output image data set according to the specifications of the electronic still camera.

For example, when the captured image data is binarized and output, the image data is binarized and output by performing a pseudo halftone process such as an error diffusion method. At this time, the threshold value and How to diffuse the error is determined by the electronic still camera.

Further, the data amount of output image data such as the number of horizontal pixels, the number of vertical pixels, and the aspect ratio of the image data output from the electronic still camera is also determined by the capability of the electronic still camera.

Further, in the exposure control at the time of photographing, since the shutter speed and the aperture value are set so that the brightness near the center of the subject image becomes a predetermined value, the exposure value of the image data is uniquely set. It is determined.

[0006]

Recently, it has been considered to use an electronic still camera as an image input terminal and connect it to various external electronic devices to capture an image. However, since the image processing capability is different for each external electronic device, the image data input according to the specifications of the electronic still camera cannot be efficiently processed.

For example, when binarizing and outputting the image data, the optimum error diffusion method differs depending on the characteristics of the display device used in the external electronic device, the type of the original image, and the intended use of the output image.

Further, the amount of image data required by the external electronic device differs due to the difference in memory capacity and display size of the external electronic device. Further, when a part of the image data is cut out and output by the external electronic device, the exposure value of the cut out image data is different from the proper exposure value set at the time of shooting because the cut image data is different from the captured subject image.

For the above-mentioned reason, there arises a problem that required image data differs depending on the external electronic equipment connected to the electronic still camera. The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic still camera capable of resetting the specifications of the electronic still camera based on the specifications of the external electronic device input from the external electronic device. And

[0010]

In order to achieve the above object, the present invention relates to an electronic still camera for picking up an image of a subject and outputting image data, in which an output image format of image data output from the electronic still camera is set. It is characterized in that it is made variable by inputting from the outside.

Further, according to the present invention, an image pickup means for picking up an object, a binarization means for binarizing the image data picked up by the image pickup means, and a binary image binarized by the binarization means. In an electronic still camera that outputs data,
The threshold value of the binarizing means of the electronic still camera is made variable by inputting it externally.

Further, the binarizing means is characterized by performing dither processing. Further, the binarizing means is characterized by performing an error diffusion process and further making it variable by externally inputting an error diffusion coefficient associated with the threshold value.

Further, according to the present invention, in an electronic still camera for picking up an image of a subject and outputting the image data, a predetermined area of the picked-up image data is converted into a data amount inputted from the outside and outputted. To do.

The amount of data input from the outside is based on the number of horizontal pixels, the number of vertical pixels, the aspect ratio, and the magnification. Also,
The present invention, in an electronic still camera for capturing an image of a subject with proper exposure and outputting image data, when a cutout region of the captured proper exposure image data is input from the outside and the exposure of the cutout region image data is captured. The feature is that correction is possible based on the proper exposure.

[0015]

According to the above-mentioned means, the present invention can output image data in an image form corresponding to an external device by changing imaged image data corresponding to an image form input from the outside. For example, since the original image data stored in the memory corresponding to the external device is binarized using the error diffusion method, the characteristics of the display device used for the external device, the type of the original image, and the output image Optimal binarization processing can be performed depending on the application, and in particular, how to disperse dots can be arbitrarily adjusted by changing the binarization threshold value and the diffusion coefficient according to an instruction from an external device.

Further, since a predetermined area of the picked-up image data is converted into a predetermined amount of data and outputted, any portion of the picked-up image data can be outputted with an arbitrary number of pixels.
It can be configured to be compatible with external devices of various specifications, and can be converted into a data amount corresponding to the memory capacity and display size of the external device.

Further, the image data in the view area is gain-corrected in order to perform gain correction on the image data obtained by cutting out a predetermined portion of the properly-exposed captured image data and to output the image data in a state equivalent to the proper exposure. Since it is possible to output the cropped image in the same state as the proper exposure at the time of shooting, especially when the view area changes momentarily due to zoom-in / out or vertical / horizontal scrolling, etc., an appropriate image can be output. Higher functionality can be achieved.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of an electronic still camera according to the present invention. In this figure, the electronic still camera is
A / D converter 31, CDS circuit 32, memory control unit 33, timing generator 34, register 35, integration processing circuit 36, counter 37, timer 38, CPU 39, parallel I / O 40, ROM 41, RAM 42, I / O
Port 43, interrupt processing unit 44, serial I / O 45,
And a system clock generator 46, and includes a memory controller 33, a register 35, a counter 37, a timer 38, a CPU 39, a parallel I / O 40, and a ROM 4.
1, the RAM 42, the I / O port 43, the interrupt processing unit 44, and the serial I / O 45 are connected to the bus 47.

The A / D converter 31 receives an A / D signal according to the processing timing signal input from the timing generator 34.
The conversion processing timing is controlled, and the image signal amplified and output from the CCD 11 by the amplifier 51 is converted into a predetermined digital image signal and output to the CDS circuit 32.

The CDS circuit 32 includes a timing generator 34.
Controlled by a sampling timing signal input from the input terminal and a predetermined control signal input via the register 35, and is superimposed on the digital image signal input from the A / D converter 31 at the output portion of the CCD 11 Correlated double sampling processing that removes reset noise, 1 / f noise, and the like is performed, and the digital image signal from which the noise is removed is output to the memory control unit 33 and the integration processing circuit 36 as image data.

The memory controller 33 includes a timing generator 3
4 is controlled by the access timing signal input from 4 and a predetermined access request signal input from the register 35, and the image data input from the CDS circuit 32 is transferred to the SRAM 52 connected to the outside for writing,
The image data is read from the SRAM 52 and transferred to the parallel I / O 40, the I / O port 43, and the serial I / O 45 via the bus 47.

The timing generator 34 is a processing timing signal for the A / D converter 31 based on the master clock signal input from the master clock generator 46.
Generating various timing signals for controlling various processing timings in the image processing circuit 30, such as a sampling timing signal for the CDS circuit 32, an access timing signal for the memory control unit 33, and an integration processing timing signal for the integration processing circuit 36. At the same time, it outputs a predetermined timing signal for controlling the operation timing of the CCD 11 in the CCD driver 53 connected to the outside.

The register 35 is a CPU via the bus 47.
Various control signals input from 39 are temporarily stored, and the various control signals are output to the CDS circuit 32, the memory control unit 33, and the integration processing circuit 36 according to the timing signal input from the timing generator 34.

The integration processing circuit 36 includes the timing generator 3
CD according to the integration processing timing signal input from
The image data input from the S circuit 32 is integrated, and the integration result is output to the counter 37.

The counter 37 counts up based on the integration result input from the integration processing circuit 36, and notifies the count value to the CPU 39 via the bus 47. The timer 38 sets a delay time or the like of the shutter operation at the time of image capturing, and the set time is set via the bus 47 to the interrupt processing unit 4.
Notify 4.

The CPU 39 executes error diffusion processing of image data based on a predetermined program stored in the ROM 41 to generate binary image data, and transfers the accumulated charge in the CCD 11 described later. Timing control processing is executed to control the electronic shutter operation in the CCD 11.

The parallel I / O 40 transmits / receives image data, control data, etc. to / from the parallel I / O of an electronic device connected to the outside in accordance with a predetermined parallel data communication procedure. The ROM 41 stores a program executed by the CPU 39, and the RAM 42 forms a data area for temporarily storing data when the CPU 39 executes error diffusion processing and the like.

The I / O port 43 is connected to an I / O port of an external electronic device or the like, and controls the transfer of image data according to a predetermined data communication control procedure. The interrupt processing unit 44
An interrupt process such as a shutter delay operation is executed according to the delay time set by the timer 38.

The serial I / O 45 is connected to the serial I / O of an electronic device connected to the outside via the bus 47.
Image data, control data, etc. are transmitted and received according to a predetermined serial communication procedure (for example, RS232C).

The SRAM 52 forms a memory area for temporarily storing image data by the memory control unit 33. The CCD driver 53 generates a frame shift pulse signal and a line transfer pulse signal for controlling operations such as a photoelectric conversion / accumulation period in the CCD 11 and a transfer timing of accumulated charges according to a timing signal input from the timing generator 34. It is generated and output to the CCD 11.

The electronic still camera is connected to an external electronic device through each I / O port, and an output image form is received from the external electronic device, so that the CPU 39 takes a captured image based on the received output image form. Optimize your data.

First, the optimization of the error diffusion processing will be described. FIG. 2A is a principle diagram showing an example of the error diffusion method, which is a method of diffusing a difference from the original luminance when a pixel is binarized to surrounding unprocessed pixels. Here, the bit width of the original image data is 8 bits (256 gradations). That is,
The pixel X is binarized X ₀ by the binarization threshold T, and X <T
Then, if X ₀ = 0 (black), and if X ≧ T, then X ₀ = 255 (white), then X−X ₀ becomes an error component. This is diffused to surrounding pixels at a predetermined ratio. In this embodiment, the error component is multiplied by the diffusion coefficient K to control the diffusion amount. As shown in the error diffusion filter of FIG. 2B, diffusion is performed in four directions, and the value D ′ (n) of the surrounding pixels D (n) after diffusion is the coefficient of the corresponding error diffusion filter. If β (n), then D ′ (n) = D (n) + β (n) ^* K ^* (X−X ₀ ), and an error is included when binarizing this pixel D ′ (n). By performing similar processing on the odd value D ′ (n), a natural image close to the density gradient of the original image can be obtained. Figure 2 (b)
In the example of the error diffusion filter of 1), the error of the binarization performed in the pixel X is calculated as each ratio 7/16, 1/16, 5/16, 3/16.
Add to surrounding pixels with.

However, when the threshold value T is changed, the lightness and darkness of the entire output image changes. The smaller the threshold value T, the brighter the image becomes, and the larger the threshold value T, the darker the image becomes. Also, the diffusion coefficient K
When (0 ≦ K ≦ 1) is changed, the total amount of diffusion is increased or decreased and the tone of the output image is changed. When K = 0, the image becomes a completely binary image without error diffusion, and as the diffusion coefficient K increases, the image becomes closer to a halftone image, but the threshold value T and the diffusion coefficient K are as shown in FIG. By making changes in relation to each other, this change can appear more natural. As described above, since the threshold value T is changed in association with the diffusion coefficient K, there is an advantage that the halftone adjustment of the image can be performed more naturally, and the parameter to be given is 1.
You can adjust the halftone with a simple operation.

That is, the ROM 41 of the electronic still camera 1
If the internal electronic device has a table as shown in FIG. 3, the external electronic device may receive either the threshold value T or the diffusion coefficient K.

As described above, when the error diffusion process is performed on the imaged image data, the error diffusion process is performed based on the threshold value or the diffusion coefficient input from the external electronic device. Optimal image data can be output to an external electronic device regardless of the characteristics of the display device of the device, the type of original image, and the use of the output image.

In this embodiment, the pseudo halftone processing is realized by the error diffusion processing, but the present invention is not limited to this, and pseudo halftone processing such as dither processing may be used. In this case, the threshold value of the dither matrix of a predetermined size, the size of the dither matrix, etc. are input from the external electronic device.

Next, an electronic still camera will be described in which the amount of data when outputting all or part of the original image can be arbitrarily changed by designation from an external electronic device. The external electronic device has a horizontal pixel number H, a vertical pixel number V, a viewpoint (C _x , C _y ), an aspect ratio A, and
The magnification Z is designated, the CPU 39 converts the image data of the portion required by the external electronic device into the required data amount based on these parameters, and sends it to the external device via each I / O port.

The basis of this operation is pixel interpolation calculation as shown in FIGS. 4 (a) and 4 (b). That is, as shown in FIG. 4A, the interpolation data S is obtained by linear approximation of the data P and Q of 2 pixels.

S = (1-d) P + dQ Then, as shown in FIG. 4B, in order to obtain the interpolated data S at one point in the area from the data A, B, C, D of the four neighboring pixels, first, Interpolation data P and Q at two points in the horizontal direction are obtained, P = (1-x) A + xB Q = (1-x) C + xD Next, the same calculation is performed in the vertical direction to obtain the target interpolation data S.

S = (1-y) P + yQ In the present embodiment, the pixels are divided into 256 to generate a virtual space having 240 ^* 120 to 61440 ^* 30720 pixels of the number of effective pixels of the original image data.

Next, as shown in FIG. 5, a region K _x ^* centered on the viewpoint (C _x , C _y ) of this virtual space ^.
The extraction of the image space for converting K _y into H ^* V pixels and outputting will be described. If data is transmitted from the upper left corner of the output screen with the horizontal direction as the main scanning direction and the vertical direction as the sub-scanning direction, the first transmission data D (0,0) is
A point on the virtual space _{(C x -K x / 2,} C y -K y / 2), the next transmission data D (1, 0) becomes K _x / H pixels right of the data. Because the vertical direction is the same, transmission data D (i, j) is, D (i, j) = (C x -K x / 2 + i * K x / H, C y -K y / 2 + j * K y / V). Here, K _x and K _y are given as K _x = k ^* A ^* H / Z K _y = k ^* a ^* V / Z k: constants using the above-described aspect ratio A and magnification Z. However, the aspect ratio A is defined as A = px / py when the pixel pitch in the horizontal direction is px and the pixel pitch in the vertical direction is py. In the formula, a is the aspect ratio of the CCD itself.

When the magnification Z is changed, zoom-in / out is performed, and when the view points C _x and C _y are changed, vertical / zoom is performed.
Horizontal scroll can be easily realized. As described above, an arbitrary portion of the original image data can be output with an arbitrary number of pixels, so that an electronic camera compatible with external electronic devices of various specifications can be configured.

Next, an electronic still camera will be described in which, when a part of the captured image is read out, exposure correction is performed so that the subject in the clipped part has an appropriate exposure and then output. That is, as shown in FIG.
Reference numeral 39 calculates an average value A of the central portion AE calculation area of the captured original image data, and performs exposure control so that this average value A becomes equal to a predetermined proper exposure value. When the original image data in the designated view area is enlarged / reduced as necessary with respect to the image data whose exposure is controlled by this proper exposure, as shown in FIG.
With respect to the cut-out view area, the average value B of the central portion AE calculation area in the view area is calculated as in the case of shooting. By performing gain correction on the image data in the view area by A / B, the cutout image can be output in a state equivalent to the proper exposure. in this case,
Limit the gain so that the image does not look unnatural due to extreme light and dark.

As described above, since the function for gain-correcting the image data in the view area is provided, there is an advantage that the clipped image can be output in a state equivalent to the proper exposure, and zoom-in / out, vertical / horizontal scrolling, etc. As a result, an appropriate image can always be output even when the view area changes momentarily, so that the electronic still camera can be made highly functional.

FIG. 8 shows an example in which the electronic still camera 1 of the present invention is connected to a label printer 61. In the figure, a label printer 61 includes a liquid crystal display screen 62 for displaying image data input from the electronic still camera 1, an operation state of the label printer 61, a contrast dial 63 for adjusting the brightness of the liquid crystal display screen 62, and a label. Of the electronic still camera 1, an operation key unit 64 for inputting characters, a character input unit 65 for inputting characters, a power key unit 66 for turning on / off the power source, and the like. Then, it is connected to the electronic still camera 1 of the present invention by a cable.

In the above configuration, the error diffusion coefficient K is determined depending on the characteristics of the liquid crystal panel (display device) of the liquid crystal display screen 62, the type of original image (for example, natural image), and the intended use of the output image, and the image memory of the label printer 61. Of the view point (C _x , C _y ), the area (K _x , K _y ), the aspect ratio A, and the magnification based on the display capacity that can be displayed on the liquid crystal panel of the liquid crystal display screen 62, the area required as image data, and the like. Z or the like is input to the electronic still camera 1 via a cable, and based on the input data, the electronic still camera 1 uses the error diffusion coefficient K as described above to perform the optimum error diffusion process and view for the label printer 61. point (C _x, C _y), the area (K _x, K _y), the aspect ratio a, the output image data of the optimum data amount and the optimum exposure value based on the ratio Z It is possible to force.

9 and 10 show the electronic still camera 1 of the present invention connected to electronic notebooks 67 and 69.
Shows that the electronic still camera 1 is formed integrally with the electronic notebook 67, and FIG.
Is connected to the electronic notebook 69 by a cable. Also in this embodiment, as described above, the error diffusion coefficient K is determined depending on the characteristics of the liquid crystal display panels 68 and 70, the type of original image (for example, natural image), and the use of the output image, and the image memory of the electronic notebooks 67 and 69. Of the viewpoint (C _x , C _x , the display size that can be displayed on the liquid crystal display panels 68 and 70, the area required as image data, etc.).
C _y ), area (K _x , K _y ), aspect ratio A, magnification Z
Electronic still camera 1 etc. directly or via cable
Based on the input data, the electronic still camera 1 uses the error diffusion coefficient K as described above to optimize the error diffusion processing for the electronic notebooks 67 and 69, the view points (C _x , C _y ), The output image data of the optimum data amount and the optimum exposure value can be output based on the region (K _x , K _y ), the aspect ratio A, and the magnification Z. Thus, the electronic still camera 1 of the present invention can
It may be formed integrally or detachably.

[0048]

As described above, according to the present invention, image data is output in an image format corresponding to an external device by changing imaged image data corresponding to an image format input from the outside. it can. For example, since the original image data stored in the memory corresponding to the external device is binarized using the error diffusion method, the characteristics of the display device used for the external device, the type of the original image, and the output image Optimum binarization processing can be performed depending on the application, and especially how to disperse dots according to instructions from external equipment,
It can be arbitrarily adjusted by changing the binarization threshold value and the diffusion coefficient.

Further, since a predetermined area of the picked-up image data is converted into a predetermined data amount and outputted, an arbitrary portion of the picked-up image data can be outputted with an arbitrary number of pixels.
It can be configured to be compatible with external devices of various specifications, and can be converted into a data amount corresponding to the memory capacity and display size of the external device.

Further, the image data in the view area is gain-corrected in order to output the image data obtained by cutting out a predetermined portion of the properly-exposed captured image data in a state equivalent to the proper exposure. Since it is possible to output the cropped image in the same state as the proper exposure at the time of shooting, especially when the view area changes momentarily due to zoom-in / out or vertical / horizontal scrolling, etc., an appropriate image can be output. Higher functionality can be achieved.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

FIG. 2 is a structural explanatory view showing an example of an error diffusion method according to the present invention.

FIG. 3 is a characteristic diagram showing an example of a relationship between a diffusion coefficient and a threshold value according to the present invention.

FIG. 4 is an explanatory diagram showing an example of pixel interpolation calculation according to the present invention.

FIG. 5 is an explanatory diagram showing an example of clipping a pixel space according to the present invention.

FIG. 6 is an explanatory diagram showing an example of an AE calculation area according to the present invention.

FIG. 7 is an explanatory diagram showing another example of clipping a pixel space according to the present invention.

FIG. 8 is a configuration diagram showing an example in which the electronic still camera of the present invention is connected to a label printer.

FIG. 9 is a configuration diagram showing an example integrally connected to an electronic notebook as another example of use of the present invention.

FIG. 10 is a configuration diagram showing an example in which a cable is connected to an electronic notebook as another example of use of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic still camera, 11 ... Frame transfer type CCD, 31 ... A / D converter, 32 ... CDS circuit, 33 ... Memory control part, 34 ... Timing generator, 3
5 ... Register, 36 ... Integration processing circuit, 37 ... Counter,
38 ... Timer, 39 ... CPU, 40 ... Parallel I / O,
41 ... ROM, 42 ... RAM, 43 ... I / O port, 4
4 ... Interrupt processing circuit, 45 ... Serial I / O, 46 ... System clock generator, 47 ... Bus, 51 ... Amplifier, 5
2 ... SRAM, 53 ... CCD driver.

Claims (7)

[Claims] 1. An electronic still camera for picking up an image of a subject and outputting image data, wherein an output image format of image data output from said electronic still camera is variable by inputting from outside. Still camera. 2. An image pickup means for picking up an object, a binarization means for binarizing the image data picked up by the image pickup means, and binary image data binarized by the binarization means. An electronic still camera, wherein the threshold value of the binarizing means of the electronic still camera is made variable by inputting from outside. 3. The electronic still camera according to claim 2, wherein the binarizing unit performs dither processing. 4. The binarizing means performs error diffusion processing,
Further, the error diffusion coefficient associated with the threshold is made variable by externally input.
Electronic still camera described. 5. An electronic still camera for picking up an image of a subject and outputting the image data, wherein a predetermined area of the picked-up image data is converted into a data amount inputted from the outside and outputted. . 6. The electronic still camera according to claim 5, wherein the amount of data input from the outside is based on the number of horizontal pixels, the number of vertical pixels, the aspect ratio, and the magnification. 7. An electronic still camera that images a subject with proper exposure and outputs image data, when the cut-out area of the imaged proper-exposure image data is input from the outside and the exposure of the cut-out area image data is imaged. An electronic still camera characterized in that it can be corrected based on the appropriate exposure of.