JPH01309474A - Electronic camera - Google Patents

Abstract

PURPOSE:To adjust the print contrast properly in a short time even if a printer represents a low gradation by using a microcomputer incorporated in an electronic camera, analyzing the density in a picture and assigning to a printer optimizingly the gradation. CONSTITUTION:A picture data displayed on a screen of a measuring instrument or the like is given to a frame memory 19 through a hood 11 or the like. The lightness and the distribution characteristic diagram of picture element number having the lightness are generated by a microcomputer 28 at printing from the data and a point (a) being a certain level SHD or below and the darkest point where the lightness is decreased monotonously is detected. Then a point (b) closest to the point (a) brighter than that at the point (a) and whose level is SHD or over is detected by increasing gradation by one and then monotonously. Then one gradation is assigned from the point (a) to the point (b) and (n-2)- gradation is assigned uniformly to remaining effective data parts. Thus, the gradation is assigned to each picture element optimizingly and each picture is printed out by a printer according to the gradation in a short time automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic camera, and particularly to an electronic camera suitable for capturing images of a tube surface for collecting data from a measuring instrument or the like.

[Conventional technology]

Traditionally, tube cameras using silver-salt Polaroid film have been widely known as cameras of this type, and although they have the disadvantage of high operating costs, they are widely used because of their relatively simple configuration. . In response to this, the inventors of the present invention have separately filed an application for an electronic camera of this type consisting of a solid-state image sensor, a frame memory, and a printer.

FIG. 5 is a block diagram showing the configuration of one of the proposed examples, and the configuration will be briefly explained below.

11 is a hood for limiting the angle of view of incidence and blocking unnecessary external light; 12 is a lens group of the imaging optical system; 13 is an aperture; and 14 is a shutter. An image projected on the tube surface of a measuring instrument or the like passes through these systems and is formed on the solid-state image sensor 15. The formed image is photoelectrically converted by the solid-state image sensor 15, and this signal is sequentially read out by the clock circuit 25. 16 is a sample hold circuit for extracting only the video signal from the signal of the image sensor 15, and from this output signal, the Y-process circuit 17 outputs T.
A V signal is generated, digitized by an analog converter 18, and a plurality of images are stored in a frame memory 19.

The shutter 14 is linked to a trigger switch 22,
The user can use this switch 22 to store images in the frame memory 19 via the controller 21. 26 is an operation panel through which the user can select the shutter speed, frame, and memory 19;
Furthermore, it instructs data transfer from the frame memory 19 to the printer 20, etc.

In addition to outputting to the printer 20, this camera also outputs to the TV.
In that case, the output from the frame memory 19 is converted into an analog quantity by the digital/analog converter 23, interpolated by the low-pass filter 24, and clamped by the clamp circuit 27. After that, the synchronization signals are synthesized and output to the TV.

Next, a method of printing captured images using a printer will be described.

As shown in Fig. 6, the gradation allocation is as shown in the explanatory diagram of the method.
Printing is performed by assigning gradation levels to each pixel using contrast data. That is, manually move the contrast value SHL to the left or right in the brightness vs. pixel count distribution map, discard levels darker than that contrast value SHL, assign one tone, and move up to the remaining maximum brightness MSB (or move the actual valid data The remaining number of gradations (n-1) are evenly allocated to the brighter side (up to the maximum brightness of the image).

[Problem to be solved by the invention]

However, this results in assigning shading to areas where there is no data, and therefore, a high gradation printer is required to obtain a clear image. Also,
Since the camera is equipped with a high-gradation display printer, the cost of the device itself is high. On the other hand, if you use a printer with a low gradation display, it is easy to think of keeping the cost low, but in such a case, the above-mentioned camera should have a better allocation of shading for printing on the printer. It was necessary to make appropriate adjustments, and it was difficult to make adjustments to obtain a clear target image, so it was necessary to make many trials.

The present invention was made in view of the problems of the conventional proposals as described above, and it is possible to achieve appropriate printing contrast in a short time even if the printer has a low gradation display in this type of electronic camera. Automatic tone allocation that can be adjusted is intended to provide a means.

[Means to solve the problem]

Therefore, the present invention attempts to achieve the above object by configuring a microcomputer built into this type of electronic camera to analyze the density in the image and optimally allocate the gradations to the printer. It is something.

[Effect]

With the above configuration, appropriate gradation assignment is automatically performed, so even when using a printer with a low gradation display, a clear image can be obtained in a short time, and when using a printer with a high gradation display, it is possible to obtain a clear image in a short time. , the image quality can be further improved.

〔Example〕

(Structure) FIG. 1 shows a block diagram of the structure of an embodiment of this type of electronic camera according to the present invention, and the same (equivalent) components as in the conventional example shown in FIG. 5 are denoted by the same reference numerals. That is, to repeat the explanation, 11 is the same hood as in FIG.
is a lens group of the imaging optical system, 13 is an aperture, 14 is a shutter, 15 is a solid-state image sensor, 16 is a sample hold circuit,
17 is a Y-process circuit for creating a TV signal, 1
8 is an analog/digital converter; 19 is a frame memory capable of storing multiple images; 20 is a printer;
1 is a controller, 22 is a shutter trigger switch, 23 is a digital/analog converter, 24 is a low-pass filter, 25 is a clock circuit, 26 is an operation panel,
27 is a clamp circuit. Further, 28 is a microcomputer (hereinafter simply referred to as a microcomputer) for converting image data provided according to the present invention.

(Operation/effect) The operation/effect in the above configuration will be explained below. The image data projected on the tube surface of the measuring instrument etc. is stored in the hood 11.
The optical system 12 . When this data is printed, the microcomputer 28 creates a distribution characteristic diagram of brightness i (brightness) and the number of pixels having that brightness, as shown in Fig. 2, an example of a density distribution diagram, and below a certain level SHD. A is the darkest point that continues to decrease monotonically.
Detect a point, use one gradation below that as a background, then monotonically increase, detect the nearest point b that is brighter than point a, and higher than SHD, then one gradation from point a to point b, and the rest. By evenly allocating (n-2) gradations to the effective data area of , the gradation is optimally assigned to each pixel, and each pixel is automatically and quickly printed at that gradation by the printer. .

(Other Examples) Note that the method of allocating the gradations is not limited to the example shown in FIG. 2.
It is possible to allocate gradations in the manner shown in the figure.

That is, in FIG. 3, the average brightness of all pixels is SHL,
One gradation below the SHL, and (n-1) gradations equally distributed between the SHL and the maximum brightness of the actual effective data.

Also, Figure 4 shows monotonous increases and decreases depending on brightness.

Divided into four areas of increase and decrease, the slope of the characteristic curve of the central two areas (decrease and increase) is linearly approximated, and the brightness value at the intersection of each linear approximation line is defined as SHL, and from this SHL the following One gradation is assigned to the brightness, and (n-1) gradations are evenly allocated between SHL' and the maximum brightness of the actual effective data.

〔Effect of the invention〕

As described above, according to the present invention, it is now possible to obtain clear images in a short time even in this type of electronic camera using a low-cost printer with low gradation display. Further, even when a printer with a high gradation element is used, gradation can be effectively assigned to the printer, so that even higher quality prints can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram of an embodiment of an electronic camera according to the present invention, and FIG. 2 is an explanatory diagram of a method for gradation assignment according to the present invention.
FIG. 3 is a diagram of the second embodiment of FIG. 2, and FIG. 4 is a diagram of the second embodiment of FIG.
Another third embodiment of the figure, FIG. 5 is a block diagram of the configuration of an electronic camera as a conventionally proposed example, and FIG. 6 is an explanatory diagram of a conventional gradation allocation method. 11...Hood 12...Imaging optical system 13...Aperture 14...Shutter 15...Solid-state image sensor 19...・Frame memory 20...Printer

Claims (2)

[Claims] (1) It has a hood for limiting the incident angle of view and blocking unnecessary external light, an imaging optical system, an aperture, and a shutter,
In an electronic camera that is equipped with an image storage means for storing one or more images in the camera that forms an image on a solid-state image sensor, and a printer, gray scale is applied only to effective pixels without the need for electrical contrast adjustment. An electronic camera characterized by being configured to assign a key. (2) When assigning the gradation to pixels, create a distribution characteristic diagram of brightness (brightness) and the number of pixels for each brightness,
2. The electronic camera according to claim 1, wherein the electronic camera is configured to assign shading to each pixel based on the distribution state.