SU39421A1 - Method and device for measuring colors and expressing them in digital values - Google Patents

Description

The proposed method for measuring colors consists in that the color test is compared with that of color reflected from a white surface and passing through a corresponding intensity of three color filters — red, yellow, and blue, the color intensity of which gradually rises from one edge to another; Integration is marked on color filters by divisions.

As is well known, white color can be obtained with help, and reflections of three primary colors — red, yellow, and blue (denoted in the drawing, L, C) and in equal amounts. Black color is obtained when it is abrupt, these colors are also completely and in equal amounts in intensity, taking the reflected rays for positive values, and absorbed rays for negative and taking the total number of rays, which, can be reflected, for the value (where and then a definite quantitative value of the reflected rays L, F. and C, which can be conventionally taken equal to eg 100), and the number of absorbed rays of the colors L, / K, C as variable values y, Y, Z, we get for white the formula / g / C -} - - | -C (all rays are reflected) a for black, the formula (n - X) K- (n - Y) (n - Z) C with

(ace the bundle is gone, ayuts). Since the process of coloring white objects in some other color is the act of reducing the number of different colored rays reflecting, any color will be expressed by the formula:

(- А) / r-f (/ г - У) Ж + («- Z) С,

i.e. each given color can be expressed by the algebraic sum of the three primary colors K,} K and C. Since the magnitude of the reflected rays is assumed constant, the full color depends only on the number of darknesses, the rays of the three primary colors. This formula, expressing all colors, including achromatic from white to black, is the basis of the method of measurement and numerical expression of any given color. If we are able to determine the values of X, K, Z, then we can express any color in numbers. Three color filters can be used to determine the values of X, Y, Z, each of which is colored in its basic color K, F or C and therefore absorbs its own rays. The color of the color filters is such that the intensity of the color on them gradually rises from one edge to the other. The degree of intensity is marked by divisions on the color filters. If you look through the color filters, folded together, so.

so that the light ends coincide with light, dark with dark, on white color, it will appear in the form of an achromatic color range from white to black. By moving the color filters, they can be found in such a way that the white color appears equally colored with the color being measured. The divisions found on the color filters in this way will give the values X, Y, Z. Substituting them into the formula (n - X) K - (n - Y) F - f (ha - Z) C, we obtain a numerical color expression.

In order to implement this method, the device shown in FIG. 1. In FIG. 2 shows a modified device, FIG. 3-device, in which two mirrors are used to mix the background of the color to be measured with the background of the color filter; in FIG. 4 shows a device in which a prism is applied for the same purpose.

The device consists of a tube 7 (Fig. 1) with an opening O for observation. The opposite end of the tube in one part is open to observe the object / 7 whose color one wants to measure. and in another part there are retractable graduated color filters K,} fC and C. through which a white object is observed B: When observing, the color filters are set so that the white color appears the same color with the measured color of the object / 7.

In order to measure the colors when illuminated with different light sources and to measure the colors of distant objects, a modification of the described device is proposed (Fig. 2).

The modified device (Fig. 2) is characterized in that instead of the white object B, white matte glass M is placed in front of the color filters, illuminated by the source of white color L.

In order to see the continuous field of the observed color with the color filter field, thin mirrors 3 and 3 (Fig. 3) or prismatic glass P (Fig. 4) are installed inside the tube in the path of the rays coming from the measured color and color filters.

The subject matter of the invention.

Claims (4)

1. A method of measuring colors of surfaces and transparent media and expressing them numerically, characterized in that the color of the test surface or transparent medium is compared with the color of the illuminated white surface viewed through three color filter-red, yellow and blue placed one after the other; gradually rises from one edge of the zeitofilter to the other and is marked on the color filters by divisions. „2. For carrying out the method according to claim 1, a device in the form of a tube, characterized in that the half of the field of view of the tube T with an opening O for observation is covered with retractable color filters / A, K, C, located against the white reflecting surface B (Fig. 1). 3. A device change under item 1, characterized in that instead of a white reflective surface B, a white frosted glass / I is placed in front of the color filters} K, K, C, illuminated by a white source (Fig. 2). 4. In the device on PP. 2 and 3, the use of mirrors 3, 3 placed inside the tube in the path of the rays (Fig. 3) or a prism P (Fig. 4) or another optical device, used to mix the background of the measured color with the background of the color filters. to the author's testimony of M. I. Vitvitsky L1 39421 at 1/7 Fip1 C to, JK ..V: 4p FIG. 2 ..-.-- t .. B-v.-1. C Oh, jfB I / p- --Fig. 3 l and g; in Jsil.0 .i: zj: - g „-.-- t JV y; oh jj