JPH1010484A - Color image recording and reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image having wide latitude by constituting a color filter of the combination of four colors R, B and two G channels having different transmissivity. SOLUTION: Among R, G and B image signals, R and B are color difference signals, so that they are not so important to gradation characteristic but G is important. The filters G1 and G2 are adjusted so that the transmissivity of the G2 may become low, and the gradation characteristic curve of the G2 is shifted to a high exposure side in comparison with that of the G1. Even in the case of using the recording medium having recording characteristic that a linear part is short and the latitude is narrow like the gradation characteristic curve of the G1 and the G2, the image is recorded in the different exposure area by changing the transmissivity of the filter. Namely, by referring to the image data of the G1 and G2, the image data where the latitude is wide like the characteristic of the G3 is generated. The data is generated buy simply taking the average value of both image data for exposure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for recording and reproducing a color image, and more particularly to a method for recording and reproducing a color image on a liquid crystal recording medium having a polymer-liquid crystal composite layer.

[0002]

2. Description of the Related Art Conventionally, an information recording medium having a liquid crystal-polymer composite layer formed on an electrode layer and an optical sensor having a photoconductive layer formed on the electrode layer are arranged to face each other. Records are known.

FIG. 1 is a diagram showing a configuration of an information recording apparatus using such an information recording medium. In the figure, reference numeral 10 denotes an optical sensor, and reference numeral 20 denotes an information recording medium. The optical sensor 10 has a transparent electrode 12 and a photoconductive layer 1 on a transparent support 11.
3 are sequentially stacked, and the information recording medium 20 is a transparent support 21.
A transparent electrode 22 and a liquid crystal-polymer composite layer 23 are sequentially laminated thereon, and a skin layer 24 is formed on the surface of the liquid crystal layer.

[0004] An optical sensor and an information recording medium as shown in FIG. 1 are opposed to each other with a gap of about 10 μm using a spacer such as polyethylene or polyimide, and a voltage application exposure is performed. 2A, a structure 40 in which an optical sensor and an information recording medium are stacked as shown in FIG.
FIG. 2A shows an example of the laminated recording medium 40.
2 (a) and 2 (b), an information recording phase is directly laminated on an optical sensor, and as shown in FIG. 2 (b), a transparent dielectric intermediate phase 25 is interposed. In the configuration shown in FIG. 1, the optical sensor 10 and the information recording medium 20 are arranged to face each other, and as shown in FIG.
When a voltage is applied between 22 and visible light is irradiated as writing light, the conductivity of the photoconductive layer 13 changes according to the exposure intensity, the electric field applied to the liquid crystal layer 23 changes, and the alignment state of the liquid crystal changes. Even after the applied voltage is turned off and the electric field is removed, the state is maintained and exposure information is recorded.

To reproduce the recorded exposure information, for example, as shown in FIG. 4, a reproduction light is emitted from a light source 31 to an information recording medium 20, and the transmitted light is read by a photoelectric conversion device 33 and converted into an electric signal. This is done by: As the light source 31, a white light source such as a xenon lamp or a halogen lamp or a laser beam is used, and as the readout light to be applied to the liquid crystal recording medium, it is desirable to select and irradiate an appropriate wavelength light by the filter 32. The incident light is modulated according to the orientation state of the liquid crystal of the information recording medium, and the transmitted light is converted into a digital signal by a photoelectric conversion device 33 including a photodiode or the like, and the converted signal is transmitted to a printer or a CRT as necessary. Is output.

[0006]

By the way, when a color image is recorded on the recording medium described above, if the recording characteristic of the recording medium is narrow (the range of the exposure amount that can be recorded is narrow), all of the recording images are recorded. There is a problem that the range cannot be recorded. For example, when a highlight portion (high exposure area) is to be recorded, the low exposure area is crushed, and when a low exposure area is to be recorded, on the contrary, the highlight portion is skipped and a good image cannot be recorded. .

[0007] The present invention has been made in view of the above point, and when recording and reproducing a color image, two exposure areas having different exposure ranges are used.
It is an object of the present invention to provide a color image recording / reproducing method for obtaining a wide latitude image by synthesizing different kinds of G image data.

[0008]

According to the present invention, there is provided a method of forming and recording a subject image modulated by a color filter on an image recording medium having an optical sensor and a liquid crystal recording medium. It is characterized by a combination of a total of four colors of two G channels having different transmittances. The present invention also relates to a method of reproducing an image recorded by being modulated by a color filter composed of a total of four colors of two G channels having different transmittances of R and B, and a G image having two different transmittances. The present invention is characterized in that data is synthesized to generate an image signal having a wide latitude.

[0009]

Embodiments of the present invention will be described below. FIG. 5 is a diagram illustrating an image recording method using a color filter. In FIG. 5A, the color filters 50 are arranged as shown in the figure immediately before the information recording medium as described in FIG. In this manner, an image is exposed through the color filter 50, and a subject image modulated by the color filter can be recorded by applying a voltage between the optical sensor and the electrode of the liquid crystal recording medium.

As shown in FIG. 5B, a color filter 50 is disposed at an image forming position of the image forming lens 80, and another color image forming apparatus 81 (relay lens) forms a color filter and an image of a subject. At the same time, an image can be recorded by a method of forming an image on an image recording medium. In this case, the subject image modulated by the color pattern of the color filter by the relay lens is formed on the image recording medium.

The spectral transmittance characteristic of the color filter is, for example, as shown in FIG. 6, and is designed to transmit light of R, G, and B basic colors, respectively. The G filter is adjusted to two types of filters G1 and G2 having different transmittances as shown in the figure. The transmittance of the G2 filter is 10 to 1 relative to the transmittance of the G1 filter.
It is designed to transmit about 5% of light. G has higher sensitivity than R and B, and the sensitivity is G1> in the present invention.
R, B> G2.

FIG. 7 shows an arrangement of the filter.
A filter in which the R, G1, G2, and B filters are arranged in a checkered pattern as shown in FIG. 7A, and a filter in which the R, G1, G2, and B filters are arranged in a stripe pattern as shown in FIG. 7B can be used.

Next, the recording image characteristics will be described. FIG. 8 schematically illustrates the gradation characteristics according to the image recording method of the present invention. The horizontal axis indicates the relative value of the exposure amount, and the vertical axis indicates the transmittance of the liquid crystal. Since R and B are color difference signals among R, G and B image signals, they are not so important for gradation characteristics.
G is important. Therefore, filters G1 and G2 are changed to G2
Is adjusted so that the transmittance of G2 becomes low.
Is shifted to the higher exposure side as compared with G1. As shown in the gradation characteristic curve for G1 and G2 in FIG.
Even when a recording medium having a short linear portion and a narrow recording characteristic is used, an image can be recorded in different exposure areas by changing the transmittance of the filter in this manner.

In the present invention, image data having a wide latitude like the characteristic G3 is generated by referring to the image data of G1 and G2. As a method of generating the image data, the average value of both image data is simply taken for each exposure amount, or the image data is synthesized by weighting one of the low exposure region, the middle exposure region, and the high exposure region For example, an appropriate method may be adopted.

Next, reproduction of a color image will be described. FIG. 9 is a diagram showing a color image reproducing method.
And a transmission image of the recording medium by using the imaging lens 41
An image is formed on the CD line sensor 60, and the transmitted image is converted into an electric signal while moving the recording medium on a stage (not shown). Since the color filter is separated from the recording medium, the reproduction light is selected and irradiated only with light of one appropriate wavelength using the bandpass filter 52, and the entire image is read by one scan. Also, the pitch of the CCD sensor is 1 with respect to the pitch of the color filter on the projected image.
The optical system is adjusted to be about 0: 1.

FIG. 10 is a diagram showing the configuration of a system for performing a color image reproduction process. The R, G1, G2, and B signals read by the CCD line sensor are first combined with G1 and G2 to generate a wide latitude G3 signal, and then combined with R, G, and B image signals to produce a reproduced image signal. Is output as

Although a full-color image using a color filter has been described above, the present invention is naturally applicable to a mono-color image. In that case, ND
By using a filter, one having a gradation characteristic in a low exposure region and one having a gradation characteristic in a high exposure region, an image having a wide latitude can be generated by combining these data.

[0018]

As described above, according to the present invention, when recording and reproducing a color image, an image having a wide latitude can be obtained by synthesizing two types of G image data having different exposure ranges. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an information recording device.

FIG. 2 is a diagram showing a configuration of a laminated recording medium.

FIG. 3 is a diagram illustrating recording of exposure information.

FIG. 4 is a diagram illustrating reproduction of exposure information.

FIG. 5 is a diagram illustrating an image recording method using a color filter.

FIG. 6 is a diagram showing the spectral sensitivity of a color filter.

FIG. 7 is a diagram illustrating a color filter of the present invention.

FIG. 8 is a diagram showing gradation characteristics.

FIG. 9 is a diagram illustrating an image reproducing method.

FIG. 10 is a diagram showing a configuration of a system for performing a color image reproduction process according to the present invention.

[Explanation of symbols]

50: color filter, 80, 81: imaging lens, G
1, G2: G filters having different transmittances.

Claims (2)

[Claims] 1. A method of forming and recording an object image modulated by a color filter on an image recording medium having an optical sensor and a liquid crystal recording medium, wherein the color filter has two G channels having different transmittances of R and B. A color image recording method comprising a combination of a total of four colors. 2. A method for reproducing an image recorded by the image recording method according to claim 1, wherein the read two-color G image data having different transmittances are combined to generate an image signal with a wide latitude. An image reproducing method, comprising: