CN85103690A - Real time pseudocolour coding device with three channels - Google Patents

Abstract

The invention belongs to an image processing device for performing false color coding on a black and white image.

The present invention uses the color separation sheet to both split light and color to form a false color coding system of a multi-channel Mach-Jeand interference ceremony with a single light source and the same optical axis, which simultaneously has multi-band synthesis, multi-channel density coding, and multi-channel space Frequency encoding, single-channel or multi-channel grating bleaching density encoding, multi-channel spatial frequency and density hybrid encoding, and laser or white light Mach-Zende interferometer capability. This system also has the ability of real-time alignment, color matching, light metering, observation and photographing of each channel.

Description

The invention belongs to an image processing device for performing false color coding on a black and white image.

The human eye is a complex discriminator. Although it usually can only distinguish more than ten gray levels, it can distinguish more than one hundred different colors. Therefore, the black and white image can be greatly improved by false coloring. The ability of humans to recognize image details.

As early as 1896, Rheinberg had used false-color-coded filters in the microscope, and in the following 90 years, many articles have introduced various false-color-coded optical methods. F.T.S.Yu made a more detailed review in his book published in 1983.

In order to synthesize the black and white pictures of the same ground feature in three different bands taken by artificial satellites with a multispectral scanner into a false color picture, the United States, Japan and my country (developed by Changchun Institute of Optics and Mechanics and East China Normal University in China) have False color synthesizers were produced separately by using one or three independent light sources and three projection lenses, which were then synthesized. This method is not only complicated in structure, requires air cooling, and is expensive, but also fundamentally lies in that it is difficult to overlap the images of the three channels because the three channels have three independent optical axes. Another disadvantage of this false color synthesis technology is that it does not have the function of Fourier transform, so it cannot be used for spatial frequency coding to improve the definition of image edges and details.

From 1981 to 1982, when Zhang Youwen was a visiting scholar at Pennsylvania State University (Pennsylvania State University), he was engaged in the research of grating bleach coding. Later, the raster method first developed into a raster bleach coding method in China, which is used for false color coding of image density. According to this principle, Sichuan University made an instrument, but because there is only one channel, it cannot perform multi-band synthesis, nor can it perform spatial frequency coding.

In 1984, Hu Guohua designed and produced a Fourier transform instrument. Although the instrument can be used for spatial frequency encoding, but because it only has a single channel, the three processes of low-pass filtering, high-pass filtering and no filtering need to be masked separately to expose the color negative film. In this way, not only the operation is complicated, but also because it is not processed in real time, it is impossible to guarantee that the image on the color negative film will not be blurred due to movement during each processing, and it is impossible to know exactly whether the color and time of each exposure are suitable. In addition, the instrument only has the function of single-channel Fourier transform, and cannot perform multi-channel synthesis.

The present invention can overcome the shortcoming of above-mentioned prior art, and its feature is that by using three channels that can simultaneously carry out Fourier transform or multi-band synthesis, only one light source, one optical axis and one Fourier transform imaging lens In the system, the real-time alignment and real-time observation of the images of the three channels are realized on a magnified screen, and the color and light intensity of each channel are adjusted in real time. . We have searched a large number of foreign patents, but none of the patents identical with the present invention have been found.

Figure 1 shows the optical schematic diagram of a real-time false color coding system with five functions of multi-band synthesis, density coding and spatial frequency coding at the same time.

Figure 2 shows the optical schematic of the spatial frequency encoding and grating bleaching encoding system.

Basic principle of the present invention is referring to accompanying drawing 1.

The light emitted from the polychromatic point light source S is collimated into parallel light by the collimator lens _L1 , and then hits the color separation film _F1 , which is a rear cut-off filter with a cut-off wavelength of 0.63μ±0.01μ , it transmits blue and green light and reflects red light. The transmitted blue and green light hits the second dichroic filter _F2 , which is a post-cut filter with a cut-off wavelength of 0.51μ±0.01μ, which transmits blue and turns green. The reflected green light hits the third dichroic filter _F3 , which is a front cut-off filter with a cut-off wavelength of 0.56μ±0.01μ, which reflects the green light and passes through the reflection from _F1 and then through the mirror _M1 Reflected red light. These green and red light are emitted to the fourth dichroic filter _F4 , which is a front cut-off filter with a cut-off wavelength of 0.48μ±0.01μ, which passes through the green and red light and reflects from _F2 The blue light that passes through and is reflected by M ₂ , so that red, green and blue light is obtained by F ₄ . In the same way, if different color filters are used as required, light of other colors can be separated.

The dotted line in Figure 1 represents the working principle of the spatial frequency encoding and grating bleaching density encoding system. At this time, a negative film (object) P _i and lens L ₂ are inserted at an appropriate position in the parallel optical path before F ₁ (enabling imaging on B′), and L ₂ performs Fourier transformation on P _i , so that Obtain their frequency spectrums on the focal points of the three channels, and then add a high-pass filter T _h to the focal point of the [1] channel, add a low-pass filter T 1 to the focal point of the [3] channel, and add a low-pass filter T ₁ to the focal point of the [2] channel. ] The image is used as the background on the channel to keep the original resolution of the image without loss (T _o in the figure means no filter is added). In this way, by removing L ₃ , a spatial frequency coded color image can be obtained on B' (the position of B' needs to be moved appropriately), in which the high-frequency part of the image (image edges and details) is red, and the low-frequency part is red. The parts (flat parts of the image) are blue and the background is green. In the layout of the optical path, the position selected by P _i can also be properly selected, so that P _i can be imaged at P ₁ , P ₂ , and P ₃ through L ₂ , and then be imaged on B through L ₃ , so that L ₃ can be kept. and B's position remains the same. If a grating bleach coded film is inserted in _Pi , and only one channel (or three channels can be used), and a small hole is used on the spectrum surface to only allow a certain level of spectrum (such as zero level or 1 level) If passed, then a density-encoded color image of image _Pi will be obtained on B'. Because the density of P _i after grating encoding and bleaching changes with the refractive index, and the refractive index is related to the wavelength, so the density changes with the wavelength, so that the corresponding different densities on B′ not only present different colors, but even small densities There will also be obvious chromatic aberration in the change, and the change is very sensitive.

The steps of grating bleaching are as follows: Use a grating of about 20 line pairs/mm to overlap a negative film with an image, and then paste them on a fresh unexposed negative film, expose it with white light, and then Develop, fix, and bleach the new film to obtain the coded input film P _i .

If the grating bleaching film is inserted into the P _i position, the [1] channel is used for density encoding, and the other two channels are spatially filtered and then used for spatial frequency encoding, then a color image that is both density-encoded and frequency-encoded can be obtained on B.

If three grating bleaching sheets of different bands are inserted at P ₁ , P ₂ , and P ₃ of the multi-band synthesis system shown by the solid line in Figure 1, and a pinhole filter is added to the focus of L ₃ , then at B The density-encoded images synthesized by different bands can be obtained on the above.

Accordingly, the present invention provides two embodiments to illustrate:

1. Insert black-and-white pictures P 1 , P 2 , and P 3 of bands 4, 5, and 7 taken by multispectral scanners on satellites or aircrafts in channels [ ₁ ], [ _2] , and [ ₃ ] respectively, and then image them Lens L ₃ just can make their color synthetic image on the screen B, this moment can use camera to take a picture, also can enlarge once and observe on a large viewing screen.

2. Insert the positive film, negative film and positive and negative film of the same medical picture on the P ₁ , P ₂ , and P ₃ film racks respectively. After the density coding of this system, the positive film will appear blue (such as bones) at this time, and the negative film will be Red (such as muscle), and intermediate density tissues are various mixed colors (such as blood vessels), thereby improving the resolution of human tissues and organs.

In summary, the present invention can be used as:

1. Three-channel synthesis of multispectral images;

2. Perform three-channel density encoding on three films (or three films with different gray levels) consisting of positive film, negative film and positive and negative film;

3. Three-channel spatial frequency encoding by adding high-pass filter, low-pass filter and no filter (or adding band-pass filter, directional filter, etc.);

4. Perform grating bleaching coding on the pictures of the three bands and then synthesize them. If necessary, one channel can also be used alone for Fourier transform to perform raster bleaching coding;

5. Use any two of the three channels, and change the color separation film into a semi-permeable film to form a laser or white light Mach-Jander interferometer;

6. The same device can simultaneously have five functions such as multi-band synthesis, three-channel density coding, three-channel spatial frequency coding, grating bleaching density coding and Mach-Jander interferometer, and can perform real-time alignment, processing, observation, Photograph.

references

① J. Rheinbevg, J. R. Microsc, Soc., p373 (August, 1896)

②F.T.S.Yu, "Optical Information Processing" Wiley, New York, 1983.

③Wang Shuying, Zhang Jingren, Peng Fanglin, Acta Optics Sinica, v.4, p528, 1984

④Hu Guohua et al., "Design of Fourier Optical Converter", internal data, 1984

⑤Zhang Youwen, "Pseudocolor Encoder Using White White Light For Geophysical And Medial Applications" to be published (finished in 1982)

⑥International patent search scope G02B, 5/18, G03B 27/32, 27/52

⑦U.S. patent search range 350/162;355/32, 67;356/123;353/87

⑧ Checked the patents of the United States, Britain, France, Japan, and Germany collected by the China Patent Office, but found no identical patents with the present invention, and no identical patents were found through computer international online searches.

Claims (11)

1, the image processing device that multifunctional real-time false color coding is carried out to black-and-white image, it is characterized in that, it is made up of following components according to the described sequence combination: ①White light or polychromatic partially coherent light source S and collimating lens _L1 , the light emitted by S is collimated into parallel light by _L1 ; ② Rear cut-off filter F ₁ with a cut-off wavelength of 0.63μ±0.01μ, used to transmit blue and green light collimated by L ₂ and reflect red light; ③ Rear cut-off filter F ₂ with a cut-off wavelength of 0.51μ±0.01μ, used to transmit the blue light passing through F ₁ and reflect the green light; ④ Mirror _M2 is used to reflect the blue light passing through _F2 ; ⑤ Mirror M ₁ is set at the position corresponding to F ₁ to reflect the red light reflected by F ₁ ; ⑥The front cut-off filter F ₃ with a cut-off wavelength of 0.56μ±0.01μ is used to reflect the green light reflected by F ₂ and transmit the red light reflected by M ₁ ; ⑦ The front cut-off filter F ₄ with a cut-off wavelength of 0.48μ±0.01μ is arranged at the position corresponding to the reflector M ₂ to transmit the red light and green light from F ₃ and reflect the light from M ₂ coming blu-ray; ⑧L ₃ is an imaging lens, which makes the color composite image composed of red, green, and blue light from the object sheet P ₁ , P ₂ , and P ₃ be mapped onto the imaging screen B; ⑨Light source S, collimating lens L ₁ , filter F ₁ , filter F ₂ , reflector M ₂ are arranged on the same axis, and reflector M ₁ , filter F ₃ , filter F ₄ , Imaging lens L ₃ , imaging screens B and B' are arranged on another axis parallel to the aforementioned axis, thus forming a multi-channel Mach system using a single light source and the same optical axis (referring to the optical axis of incoming light and outgoing light). - Real-time false color coding system for Jende Intervention Ritual. 2. The multifunctional real-time false color coding image processing device according to claim 1, wherein the P ₁ , P 2 , and P 3 placed in the channels [1], [ ₂ ], and [ _3] are of different bands The black-and-white images are synthesized by the system in multiple bands, and the color and light intensity of each channel are adjusted in real time, so that the color composite images can be aligned and observed in real time on the imaging screen. 3. The image processing device for multifunctional real-time false color coding according to claim 1, wherein P ₁ , P ₂ , and P ₃ are positive film, negative film, and positive and negative film respectively, and the system performs multi-channel density coding on them, By adjusting the color and light intensity of each channel in real time, the color composite image can be aligned and observed in real time on the imaging screen. 4. The image processing device of multifunctional real-time false color coding according to claim 1, wherein the lens _L2 is positioned before the optical filter _F1 , and the object sheet _Pi is positioned between _L1 and _L2 , and the system pairs inserted The object slice P _i is subjected to Fourier transform, so that the frequency spectrum of the object slice can be obtained at the focal points of the three channels. 5. The image processing device for multifunctional real-time false color coding according to claim 4, wherein a high-pass filter T _h is added to the focus of the [1] channel, and a low-pass filter is added to the focus of the third channel The device T ₁ uses the image as the background on the second channel (T ₀ means no filter), and obtains a color image encoded by spatial frequency on the imaging screen B'. 6. The multifunctional real-time false color coding image processing device according to claim 5, wherein the position of P _i can be adjusted appropriately so that P _i can be imaged at P ₁ , P ₂ , and P ₃ through L ₂ , and then imaged on B through L ₃ , so that the positions of L ₃ and B can remain unchanged. 7. The image processing device for multifunctional real-time false color coding according to claim 4, wherein, P _i is a grating bleach coded slice, using a certain channel (for example, the first channel) to allow only a certain level on the spectrum plane The spectrum is passed through to obtain a density-encoded color image of the image _Pi at B'. 8. According to claim 5 or 7, the multifunctional real-time false color coded image processing device, wherein, P _i is a grating bleach coded sheet, one of the three channels is used for density coding, and the other two channels are spatially filtered After spatial frequency encoding, a color image that is both density-encoded and frequency-encoded can be obtained on B. 9. The multifunctional real-time false-color coding image processing device according to claim 2, wherein P ₁ , P ₂ , and P ₃ are three grating bleaching sheets of different wave bands, and a focal point of L ₃ is added A small hole, on B, a density-encoded image synthesized by different bands is obtained. 10. According to claim 7 or 9, the multi-functional real-time false-color coding image processing device, wherein the grating bleaching is to overlap the grating of about 20 line pairs/mm on a negative film with an image, and then They are attached to a fresh, unexposed negative, exposed to white light, and the new negative is developed, fixed, and bleached. 11. The multifunctional real-time false-color coding image processing device according to claim 9, wherein the optical filters F ₁ , F ₂ , and F ₃ are changed into semi-permeable membranes, and two channels are randomly selected to form a light source of Mach-Jand interferometers for laser, quasi-monochromatic or white light.

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