DE2941841A1 - METHOD FOR GENERATING A COLOR IMAGE IN A COLOR DISPLAY SYSTEM AND COLOR IMAGE CIRCUIT USED THEREFOR - Google Patents

Description

Patent attorneys Dipl.-Ing. H. Weickmann, Dipl. Phys. Dr. F. Fincke

D ι PL.-Ing. FAWeickmann, Dipl.-Chem. B. Huber Dr. Ing.H. Liska ^ _{ζ 29Α1841}

XI

8000 MOK ¹ CHEN 86, DEN

BOX 86CS20

MOHLSTRASSE 22, CALL NUMBER 98 39 21/22

TEKTRONIX, INC.
14150 SW Karl Braun Drive
"Beaverton, Oregon 97077
V. St. A.

Process for generating a color image in a color display system and usable therein

Color mapping circuit;

030017/0898

Patent attorneys Dipl.-Ing. H. We ick mann, Dipl.-Pm s.Dr. K. Fi ν (ke

Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber Dr. Ing.H. LiSKA 29 A 1 8 4

8000 MUNICH 86, DEN

POST BOX S60 820

MÖHLSTRASSE 22, CALL NUMBER 98 3921/22

Description no

The invention relates to color display systems and, more particularly, to those systems using sov. ^{Allow r} ohl to display numeric as well as graphic characters.

In known color display systems, such as those for example in US Pat. No. 3,771,155, the different colors in which information is presented are indicated can be formed by the fact that certain fixed fourths of the three basic colors red, green and blue with each other be combined. This is most commonly done through the use of a three electron gun Color picture tube or color cathode ray tube causes whose electron guns can be activated selectively to emit electron beams of a specified specific density to create. These electron beams in turn activate the associated phosphors on the screen the picture tube or cathode ray tube in order to provide a multicolor display or representation in a conventional manner to deliver.

A particular disadvantage of the previously known color display systems is that the colors used for the display or representation can only be selected in terms of color values or tones or only in terms of color. In other words, this means that the electron guns provided for the colors red, green and blue are either completely on or completely off, and

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depending on your selection. The colors generated in this way are either in their full brightnesses or intensities present or completely absent. This inability to choose colors in values other than the color value, brings with it a considerable restriction in the intelligibility or clarity of the image display, in particular when the representation in question contains excessively compressed or accumulated information.

Accordingly, there is a need for a color display system which is capable of providing a color display in colors which are characterized by dimensions other than the color value alone. The invention is therefore the object to create a system for delivering a color display in which colors are in their hue, their saturation and brightness can be selected.

The invention is accordingly based on the object of a color display system in which the colors are selected in terms of color value or hue, saturation and brightness can be. In addition, a method for delivering a color display is to be created in which the representation of the colors takes place using their color value of the saturation and the lightness. In the end a display system is to be created which allows the easy selection of any particular number of each other exclusive display representations enabled.

The object indicated above is achieved by the invention covered in the patent claims.

According to the invention, a color display system is provided, which is able to provide a color representation in which the colors in the extent of the color value, the saturation and brightness can be selected. In addition, the present invention includes a color imaging

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circuit and an operating method with the aid of which a digital color code comprising m bits is ^{mapped in any of 2 m of} the 2 ⁿ possible digital color codes comprising η bits, with such codes comprising η bits then being converted into analog color signals of variable sizes which are used for Control of the density of the electron beams are used, which are generated by the electron guns in a conventional three electron guns using color picture tube.

The terms "color value", "lightness" and • 'saturation used here are understood in their standard definitions. Accordingly, the term "color value" means the contribution of colors which enables them to be classified as red, green, blue or as an intermediate color between any two of these colors. The term "saturation ¹¹ v: is understood to mean the extent of the difference from the gray value kit of the same brightness. The term" brightness "is understood to mean the addition of colors through which an object ε, Ιε more or less reflects or transmits light of the incident light A method of selecting an image to be formed is also provided in which the color mapping circuit is used to select any one of a number of mutually exclusive displays.

The invention is explained in more detail below with reference to drawings, for example.

Fig. 1 shows a link diagram in a color display system including a color mapping circuit according to the present invention. Fig. 2 shows a conceptual diagram of a 3-level memory cell.

Fi £. FIG. 3 shows an addressing table implemented as an example and a memory map for a color map module of FIG

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Color mapping circuit shown in Fig. 1. Fig. 4 is a conceptual diagram showing a second 3-level memory cell.

Figure 5 shows an addressing table and three alternatives Memory plans for the color plan module of the color mapping circuit according to FIG. 1.

In Fig. 1, a color display system is shown, which the color picture circuit or Farbabbildunr: c circuit according to of the invention. It can be seen that includes the through a dashed line 12 enclosed color image circuit 10 a digital register 22, a color image module 24, ... a Z-axis circuit 26 and a mapping control circuit 28. In addition to the color mapping circuit 10, the color display system contains an associated memory module 20, a cathode ray tube type display device 30, a display controller 32, a Processor 34, a dig / retrieve device 36, and a system controller 38. These circuit devices are connected to one another in the manner shown in FIG. From Fig. 1 are for the sake of clarity such other conventional circuits as power supply circuits and the like are omitted, which are necessary for the formation of a workable system.

The memory module 20 may be any suitable random access memory device that is capable of receiving and storing alphanumeric and graphic information in digital form and that is capable of transferring such information to the register 22 upon command from the processor 34. According to one embodiment of the specified circuit arrangement, a read only memory module (ROM) is used to store alphanumeric standard information, and a memory module (RAM) with random access is used by the computer or processor

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store generated graphic information.

The color map module 24 may be any suitable random access memory device having the required number of input and output ports. In the following description, the color map module 24 is viewed as an arrangement consisting of an 8 to 6 random access memory module having three input address ports 23 and six output data ports 25. It should be noted that other suitable configurations without departing from the present invention uses y referenced to earth ground.

As shown in Fig. 1, the color image circuit 10 can be used the present invention to include a three-bit data word which is indicative of a image to be formed on the screen 40 of the display device 30. The relevant color picture circuit 10 is capable furthermore, to map the data word into any of eight data words comprising six items that are selected from a group are selected from 64 possible data words, each comprising six bits, which are characteristic of the Color strength of the express, in a sense in three dimensions of color value, saturation and lightness set. In a particular device in which the color picture circuit 10 according to FIG. 1 has been incorporated, the alphanumeric and graphic information is stored in the memory in the form of memory cells, which according to the concept comprises 14 lines of 8-3it-V.'words, each of which has three bits or three levels is deep. Such a cell is illustrated in FIG. 2, the three levels of the cell with P.1, P.2 and P.O. Every 3-bit word that the Bit from the respective level P.0-P.2, defines a single memory cell, which is referred to below as a picture element Reference is made, whereby it should be understood that

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that each picture element defines a certain information scent, which is shown on the display screen 40 of the display device 30 can be displayed.

In a conventional color display system, the 3-bit word each picture element is used to determine the color properties of its corresponding information point to be determined solely with regard to the color value. This means that the definition of the basic combinations The three main colors red, green and blue are made, with each main color either in its full intensity exists or is completely absent. In the circuit arrangement according to the invention, the three bits are used to define a color image address (CMA), which is used for this purpose, a six comprehensive one Generate color image number (CMN) showing the color properties of the data point in all three dimensions the color value, the saturation and the lightness. Thus a determination is made both with regard to the changeable color strength as well as with regard to the presence of the respective color. Such a color image address 50 is shown in FIG. 1 as occurring at the three input address connections 23 of the color image module 24 Address indicated. A color image number 52 is shown as one occurring at the six output data terminals 25 Number indicated.

The operation of the color picture circuit shown in FIG 10 and the flow of the method according to the present invention are best understood with reference to a specific bit mapping configuration for the color image module 24 can be understood. Such a bit map configuration is illustrated in Figure 3, each with a different number of 64 possible color map numbers each one of the eight possible combinations of the color map address is allocated. To achieve a

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For easy understanding, the three Eits of the color map address are labeled A.2, A.1 and AO, respectively. The six bits of the color map number are plotted in pairs to indicate their relationship to the primary colors. The designations RR = red, GG = green and BB-blue have been chosen. Each digital value, represented by the two bits of a particular bit pair of the color map number, defines the intensity fczv. Brightness of its associated color (O0 = IIull brightness: t, 01 = 1/3 brightness, 10 = 2/3 brightness, 11 = full brightness). As already stated above, the six-bit color image numbers deliverable by the color image or color image module 24 can assume any one of 64 possible forms, with only eight such numbers being able to be selected by means of a three-bit color image address (in In general, of course, a 2 ^m -to-n color image module is assumed, wherein an m-bit color image address can be used to select any of the 2 ⁿ numbers out of 2 ⁿ possible color image numbers, each comprising η bits.) The selected color image numbers are stored in the color image module 24 loaded in conventional fashion via processor 34 and mapping control circuit 26; the numbers concerned can be changed at any point in time to effect program control or operator control of the color imaging process.

In operation, the system shown in Figure 1 calls a display on the display screen 40 of the display device 30 emerges in a grid line arrangement by in a buffer memory - the for example is accommodated in the memory module 20 - a complete row of selected memory cells merged or is composed and by each row of the cell row to the display device 28 in a serial fashion oriented to the image carrier

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29A1841

is delivered. As indicated above, each picture element is three bits deep, with all three bits from the memory module 20 via the register 22 to the color image module 24 with formation of the color image address 20 be transmitted at the same time. At this point it is assumed that each level of the cell shown in FIG Contains data relating to the same information, that is, that with the letter E indicated by small characters χ and with the one indicated by small + The diagonal graphic line shows the color image address 000 associated with the upper right picture element 60 and according to the bit map shown in Fig. 3 from the color image module 24 into a six-bit format Σ- «rbbildzahl will be implemented, which consists of a total of zeros. This indicates that the specific point corresponding to the picture element 60 on the display surface 40 of the display image device 26 should not be illuminated or black. The color value of the six-bit color image number is thus obtained from the Z-axis circuit 26 interpreted, with the result that none of the three color electron guns within the Cathode ray tube of the display device 28 is activated.

As illustrated by the diagram of Fig. 3A, each digital value becomes each color image number bit pair converted to an analog signal by the Z-axis circuit 26 in a conventional manner, its Size corresponds to the digital value. The analog signal is used to determine the density of the generated within the display device 30 corresponding electron beam to generate a to control predetermined display presentation. Although only the RR (red) bit pair and the corresponding analog R signal are indicated in Fig. 3A, it should be understood that a corresponding relationship between your Eitpaar GG and BB and the analog signals G and B are available

0300 17/0898

Now consider the picture element 62. The color image address of this picture element will be 101, and the Color image number will - again according to the example according to FIG. 3 - be given with 001100. This is used for generation a green one. Full brightness display patch at the point indicated by the picture element on the display screen 40. The last example ν e is the picture element 64 of the data cell according to FIG. a color image address of 110, which leads to the output of a color image number with a value of 010101. This calls the creation of a white display spot with a 1/3 brightness on the display screen 40 emerges. In order to leads the information given in the cell of FIG. 2 to the fact that from the display device 30 a green Letter L / full brightness is generated by a white diagonal line with a '/' - brightness is superimposed. The colors are determined by the digital values of the preselected color image numbers set. As will be apparent to those of ordinary skill in the art, Other configurations of the color image module can be used to that contained in the cell of FIG Information in any of the 64 possible combinations of color value, saturation and lightness to display.

An important feature of the color picture circuit 10 according to the present invention is that this circuit can also be used, under a program control, any of the three mutually independent to select images to be formed. Since, as already indicated above, each picture element is three bits deep, is also any display representation formed from a plurality of such picture elements three bits or Levels deep. Usually the 3-3it depth becomes one

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certain representation - as has already been explained above - used a multicolored Display. However, it is also possible through selective programming of the color image module 24 to use the 3-bit depth of the respective cell for three mutually independent information levels to be defined, each of which can be independently selected for purposes of illustration.

Taking advantage of this level selection property of the Color picture circuit according to the invention may also best be explained with reference to an example. In Figure 4, three levels 70, 72 and 74 of a simplified 4 by 3 pixel memory cell are illustrated. Although the three levels 70 to 74 are lying side by side as illustrated, they conceptually exist as parts of a single cell, as referenced above on Fig. 2 has been described. If the small characters χ in Fig. 4 are interpreted as positive data bits, then the information contained in level 74 of the simplified cell can be interpreted as the letter "C" and the information contained in levels 72 and 70 can be written as the letter "I" and the letter "L" can be interpreted. As before, assume that the bits at levels 74, 70 and 72 are bits 2, 1 and 72 respectively. of the respective picture element and thus of the respective color picture address word. The color image address for the upper left pixel 80 is given by 101; the address for the middle picture element 82 is given with 110, and the address for the upper right picture element 84 is given with 100. If the color picture module 24 has, for example, a configuration corresponding to the color image 90 according to FIG. 5, then generated each color image address with a 0 in bit position 2 is a color image number that contains a total of zeros. Every Color image address with a 1 in bit position 2, on the other hand, will generate a color image number that is a total of

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consists of ones. Thus only those contained in the plane 74 of the cell according to FIG. 4 influence Bits the color electron guns of the display device 30. Accordingly, the generated representation be a white letter "C" full of brightness.

If the color image module 24 is now redesigned in accordance with the color plan 92 according to FIG. 5, each Color image address with a bit defined in bit position 1 provide a color image number which is given through 111100. The other color image addresses lead to color image numbers which consist of all zeros. That The result of this is that only a yellow letter "I" is displayed. If the color image module 24 accordingly the color plan 94 according to FIG. 5 is set, in a corresponding manner only a green letter is used "L" is displayed. It should be understood that the bit maps 90, 92 and 94 according to FIG. 5 are designed in this way that only representations in white, yellow or green and in full brightness have been delivered. However, it should be evident that other color values and brightnesses have also been selected for the representations can be, as has been carried out above.

The invention therefore provides a circuit arrangement and a method for selectively imaging a first Digital signal, which is characteristic of an image to be generated, created in a second digital signal, which is characteristic of the color quality of the image in terms of color value, saturation and Brightness. Furthermore, a method is created which uses such a mapping circuit to produce a Select the particular picture to be created from a group of pictures that are a multitude of each other Contains independent images.

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Claims (11)

Pate nt a NVialte Dipl.-Ing. H. We ic km an ν, Dipl.- Ph ys. Dr K.Iincke Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Hiber Dr. Ing.H. Li ska 81 8OCO MUNICH 86, DEN BOX 86G820 MOHLSTRASSE 22, CALL NUMBER 98 39 21/22 Claims Method for generating a color image in a color display system, characterized in that a) that an identifier for a picture to be generated first digital signal is recorded, b) that the first digital signal in question is selectively mapped into a second digital signal which is characteristic of the color quality of the image in question the color value, saturation and lightness, c) and that the relevant second digital signal in a visual representation of the relevant color image implemented in terms of selected sizes in terms of hue, saturation and brightness will. 2. The method according to claim 1, characterized in that m bits are used for the first digital signal, that η bits are used for the second digital signal, where η is greater than m, and that for the selective mapping of the first digital signal in a second digital signal, the mapping of the m bits of the first digital signal in a 2 ^m combination of 2 ⁿ possible combinations of the η bits of the second signal is carried out. 3. The method according to claim 2, characterized in that that the conversion of the second digital signal into a visual representation is carried out in that a selected pair of bits of the second digital 030017/0898 Signal is converted into an analog signal with a size that corresponds to the digital value of the relevant Bit pair corresponds, and that the relevant analog signal is then used to control the density an electron beam generated within a color display system (30) is, whereby by the density of the electron beam in question the intensity of a preselected Color component of the visual representation is determined. 4. Verfanren according to claim 2 or 3, characterized in that m = 3 and n = 6 are selected. 5. A method for selecting an image to be formed in a color display system according to any one of the claims 1 to 4, characterized in that a) that a first digital signal is recorded, which is characteristic of a large number of images to be formed, b) that the relevant first digital signal is selectively mapped into a two digital signal which is characteristic of a selected image of the images in question, where through the second digital signal in question with regard to the color quality of the selected image the color gate, the saturation and brightness can be set, c) and that the relevant second digital signal in a visual representation of the selected color image is implemented, the colors of which are determined in terms of hue, brightness and saturation are. 6. color mapping circuit for performing the method according to any one of claims 1 to 5, characterized marked, 030017/0898 29A1841 a) that a signal receiving device (22) is provided, the one for a to be generated Records the first digital signal characterizing the image, b) that an imaging device (24) is provided, which selectively the first digital Able to map the signal into a second digital signal, which is characteristic of the color quality of the relevant image in terms of hue, saturation and brightness, c) and that a conversion device (26) is provided which the second digital signal in question converts its colors into a visible color image through the hue, saturation and brightness are selected. 7. color mapping circuit according to claim 6, characterized in that a digital signal comprising m bits is used as the first digital signal, that a digital signal comprising η bits is used as the second digital signal, where η is greater than m, and that the mapping device ( 24) is designed so that it maps the m bits of the first digital signal in 2 ^m combinations of 2 ⁿ possible combinations of the η bits of the second digital signal. 8. color mapping circuit according to claim 7, characterized in that the converting device (26) converts a selected pair of bits of the second digital signal into an analog signal with a magnitude. sets, which corresponds to the digital value of the relevant bit pair, and that a control device (26) is provided which, depending on the analog signal in question, the intensity of a selected color component of the display controls. 030017/0898 -U- 9. color mapping circuit according to claim 7 or 8, characterized in that m = 3 and n = 6. 10. color imaging circuit according to claim 2, characterized in that the imaging device (2U) has a memory module with random access and that the relevant memory module m input ■ 'address connections and η output data connections having. 11. Color display system according to one of claims 6 to 10, with a signal generating device for generating a digital signal which is characteristic for the color value properties of an image to be generated, and with a conversion device which converts digital signal into a visible egg, whose colors are determined by the color value properties are characterized by a ) that between the image generation device (30) and the conversion device (22) an imaging device (24) is effectively inserted, which converts the relevant digital signal into a second digital signal which is characteristic of the color quality of the image in terms of hue, saturation and the brightness, b) and that the second digital signal in a representation in the relevant conversion device of a visible image is implemented, the colors of which by preselected sizes with regard to the Hue, saturation and lightness are specified. 030017/0898