CN104568156A - Target color contrast testing device and method - Google Patents

Abstract

The invention provides a target color contrast testing device and method. The device is formed by an optical imaging system, an RGB filtering system, an area array CCD acquisition system, a computer measurement and processing system and an optical platform. The optical imaging system is aligned to a target and a background, optical signals emitted by the target and the background or optical signals only emitted by the background pass through the optical imaging system and are then subjected to light distribution through the RGB filtering system and finally imaged on the area array CCD acquisition system, and output signals of the area array CCD acquisition system are fed into the computer measurement and processing system. A CIE1964-UCS standard chromaticity theoretical evaluation system is adopted, and comprehensive calculation of three attributes, such as the brightness index W* and chromaticity indexes U* and V*, of colors is achieved; meanwhile, influences of brightness and chromaticity of the target are considered, objective evaluation target color contrasts are comprehensively evaluated, and visible light stealthy target color contrast measurement is achieved.

Description

Targeted color contrast proving installation and method of testing

Technical field

The invention belongs to optical metrology and field tests, relate generally to a kind of method of testing of target contrast, particularly relate to a kind of method of testing of targeted color contrast.

Background technology

Targeted color contrast is the fusion of brightness and colourity, different brightness, different colourity, then the contrast of target is different, and therefore, the colour contrast of goal in research will consider the impact of brightness and colourity two aspects simultaneously.Luminance contrast describes the ratio of object brightness and the brightness of environmental background, it mainly reflects the light levels between object and background, but luminance contrast can not describe the chromatic characteristic of object and background completely, Chromatic Contrast's present stage mainly adopts spectral power method to test, but, the method does not consider the vision function V (λ) of human eye when spectral power integral and calculating, its test result does not meet colourity theory.

At present, also do not see meet luminosity and colourity theory can the relevant report of accurate thoroughly evaluating targeted color contrast measuring method.

Summary of the invention

The present invention is directed to a difficult problem for targeted color contrast test, set up a set of the targeted color contrast proving installation and the method for testing that meet luminosity and colourity theory in certain circumstances, by setting up colour contrast test mathematical model, carried out the test of targeted color contrast under certain background environment by computer measurement software.

Technical scheme of the present invention is:

Described a kind of targeted color contrast proving installation, is characterized in that: be made up of with disposal system and optical table optical imaging system, RGB filter system, area array CCD acquisition system, computer measurement; Target and background thereof, optical imaging system, RGB filter system, area array CCD acquisition system are arranged on optical table successively, RGB filter system, area array CCD acquisition system and computer measurement and disposal system have data and signal mutual; Optical imaging system aims at the mark and background, target and background or be only the light signal of background emission after optical imaging system, then through the light splitting of RGB filter system, finally imaging in area array CCD acquisition system; The output signal of area array CCD acquisition system sends into computer measurement and disposal system.

Described a kind of targeted color contrast method of testing, is characterized in that: comprise the following steps:

Step 1: optical imaging system aims at the mark and background, gathers the light signal of target and background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _r(i, j), V _g(i, j), V _b(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 2: the V that step 1 is obtained _r(i, j), V _g(i, j), V _b(i, j) colorimetry formula is substituted into, obtain the color tristimulus values X (i of each pixel point of area array CCD, j), Y (i, j), Z (i, j), and by the lightness index W (i of following formulae discovery target, j) * and chromaticity index U (i, j) *, V (i, j) *

$\left\{\begin{array}{c}W{(i,j)}^{*}=25Y{(i,j)}^{1/3}-17\\ U{(i,j)}^{*}=13W{(i,j)}^{*}\×[u(i,j)-u_0]\\ V{(i,j)}^{*}=13W{(i,j)}^{*}\×[v(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}u(i,j)=\frac{4X(i,j)}{X(i,j)+152Y(i,j)+3Z(i,j)}\\ v(i,j)=\frac{6Y(i,j)}{X(i,j)+15Y(i,j)+3Z(i,j)}\end{array}\right.$

U ₀, v ₀it is the chromaticity coordinates of lighting source color;

Step 3: remove target, optical imaging system aims at background, gathers the light signal of background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _rb(i, j), V _gb(i, j), V _bb(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 4: the V that step 3 is obtained _rb(i, j), V _gb(i, j), V _bb(i, j) substitutes into colorimetry formula, obtains the color tristimulus values X of each pixel point of area array CCD _b(i, j), Y _b(i, j), Z _b(i, j), and by the lightness index W of following formulae discovery background _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *

$\left\{\begin{array}{c}{W}_b{(i,j)}^{*}=25Y_b{(i,j)}^{1/3}-17\\ U_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[u_b(i,j)-u_0]\\ V_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[v_b(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}{u}_b(i,j)=\frac{4X_b(i,j)}{X_b(i,j)+152Y_b(i,j)+3Z_b(i,j)}\\ v_b(i,j)=\frac{6Y_b(i,j)}{X_b(i,j)+15Y_b(i,j)+3Z_b(i,j)}\end{array}\right.$

Step 5: the lightness index W of the background that lightness index W (i, the j) * of the target obtained according to step 2 and chromaticity index U (i, j) *, V (i, j) * and step 4 obtain _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *, calculates the colour contrast D (i, j) of target according to the following formula:

D(i,j)＝{[W(i,j) ^*-W _b(i,j) ^*] ²+[U(i,j) ^*-U _b(i,j) ^*] ²+[V(i,j) ^*-V _b(i,j) ^*] ²} ^1/2。

Beneficial effect

Overall technology effect of the present invention is embodied in following two aspects:

1) the present invention adopts CIE1964-UCS standard colorimetric theoretical evaluation system, three attribute synthesis of the colors such as lightness index W* and chromaticity index U*, V* are calculated, consider the brightness of target and the impact of colourity two aspects simultaneously, more thoroughly evaluating objective appraisal targeted color contrast, solves the difficult problem that visible light stealth targeted color contrast is measured.

2) targeted color contrast measurement mechanism structure of the present invention is simple, easy to operate, can evaluate by realize target color contrast 3 D stereo, further increases the recognition capability to target.

Accompanying drawing explanation

Fig. 1 is targeted color contrast proving installation schematic diagram.

Embodiment

Below in conjunction with specific embodiment, the present invention is described:

In order to the test of realize target colour contrast, general plotting of the present invention is, the new method that a kind of targeted color contrast is evaluated is proposed, the method is by setting up targeted color contrast proving installation, adopt RGB three-colour filter, respectively the lightness index of target and background and chromaticity index are calculated, consider the impact of brightness and colourity simultaneously, the more comprehensive and objective appraisal colour contrast of target.The method can describe the chromatic characteristic of object and background completely, achieves the test of targeted color contrast.

As shown in Figure 1, targeted color contrast proving installation is made up of with disposal system and optical table optical imaging system, RGB filter system, area array CCD acquisition system, computer measurement; Target and background thereof, optical imaging system, RGB filter system, area array CCD acquisition system are arranged on optical table successively.RGB filter system, area array CCD acquisition system and computer measurement and disposal system have data and signal mutual, wherein computer measurement selects different optical filters from disposal system control RGB filter system, and area array CCD acquisition system outputs signal to computer measurement and disposal system.Optical imaging system aims at the mark and background, target and background or be only the light signal of background emission after optical imaging system, then through the light splitting of RGB filter system, finally imaging in area array CCD acquisition system; The output signal of area array CCD acquisition system sends into computer measurement and disposal system.

Adopt the concrete steps of above step realize target colour contrast method of testing as follows:

Step 1: optical imaging system aims at the mark and background, gathers the light signal of target and background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _r(i, j), V _g(i, j), V _b(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 2: the V that step 1 is obtained _r(i, j), V _g(i, j), V _b(i, j) colorimetry formula is substituted into, obtain the color tristimulus values X (i of each pixel point of area array CCD, j), Y (i, j), Z (i, j), and by the lightness index W (i of following formulae discovery target, j) * and chromaticity index U (i, j) *, V (i, j) *

$\left\{\begin{array}{c}W{(i,j)}^{*}=25Y{(i,j)}^{1/3}-17\\ U{(i,j)}^{*}=13W{(i,j)}^{*}\×[u(i,j)-u_0]\\ V{(i,j)}^{*}=13W{(i,j)}^{*}\×[v(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}u(i,j)=\frac{4X(i,j)}{X(i,j)+152Y(i,j)+3Z(i,j)}\\ v(i,j)=\frac{6Y(i,j)}{X(i,j)+15Y(i,j)+3Z(i,j)}\end{array}\right.$

U ₀, v ₀it is the chromaticity coordinates of lighting source color;

Step 3: remove target, optical imaging system aims at background, gathers the light signal of background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _rb(i, j), V _gb(i, j), V _bb(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 4: the V that step 3 is obtained _rb(i, j), V _gb(i, j), V _bb(i, j) substitutes into colorimetry formula, obtains the color tristimulus values X of each pixel point of area array CCD _b(i, j), Y _b(i, j), Z _b(i, j), and by the lightness index W of following formulae discovery background _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *

$\left\{\begin{array}{c}{W}_b{(i,j)}^{*}=25Y_b{(i,j)}^{1/3}-17\\ U_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[u_b(i,j)-u_0]\\ V_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[v_b(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}{u}_b(i,j)=\frac{4X_b(i,j)}{X_b(i,j)+152Y_b(i,j)+3Z_b(i,j)}\\ v_b(i,j)=\frac{6Y_b(i,j)}{X_b(i,j)+15Y_b(i,j)+3Z_b(i,j)}\end{array}\right.$

Step 5: the lightness index W of the background that lightness index W (i, the j) * of the target obtained according to step 2 and chromaticity index U (i, j) *, V (i, j) * and step 4 obtain _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *, calculates the colour contrast D (i, j) of target according to the following formula:

D(i,j)＝{[W(i,j) ^*-W _b(i,j) ^*] ²+[U(i,j) ^*-U _b(i,j) ^*] ²+[V(i,j) ^*-V _b(i,j) ^*] ²} ^1/2。

After obtaining the colour contrast D (i, j) of target, be that coordinate axis is depicted as colour contrast three-dimensional graph by targeted color contrast with i, j, D.

Claims (2)

1. a targeted color contrast proving installation, is characterized in that: be made up of with disposal system and optical table optical imaging system, RGB filter system, area array CCD acquisition system, computer measurement; Target and background thereof, optical imaging system, RGB filter system, area array CCD acquisition system are arranged on optical table successively, RGB filter system, area array CCD acquisition system and computer measurement and disposal system have data and signal mutual; Optical imaging system aims at the mark and background, target and background or be only the light signal of background emission after optical imaging system, then through the light splitting of RGB filter system, finally imaging in area array CCD acquisition system; The output signal of area array CCD acquisition system sends into computer measurement and disposal system.

2. utilize device described in claim 1 to carry out a method for targeted color contrast test, it is characterized in that: comprise the following steps:

Step 1: optical imaging system aims at the mark and background, gathers the light signal of target and background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _r(i, j), V _g(i, j), V _b(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 2: the V that step 1 is obtained _r(i, j), V _g(i, j), V _b(i, j) colorimetry formula is substituted into, obtain the color tristimulus values X (i of each pixel point of area array CCD, j), Y (i, j), Z (i, j), and by the lightness index W (i of following formulae discovery target, j) * and chromaticity index U (i, j) *, V (i, j) *

$\left\{\begin{array}{c}W{(i,j)}^{*}=25Y{(i,j)}^{1/3}-17\\ U{(i,j)}^{*}=13W{(i,j)}^{*}\×[u(i,j)-u_0]\\ V{(i,j)}^{*}=13W{(i,j)}^{*}\×[v(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}u(i,j)=\frac{4X(i,j)}{X(i,j)+15Y(i,j)+3Z(i,j)}\\ v(i,j)=\frac{6Y(i,j)}{X(i,j)+15Y(i,j)+3Z(i,j)}\end{array}\right.$

U ₀, v ₀it is the chromaticity coordinates of lighting source color;

Step 3: remove target, optical imaging system aims at background, gathers the light signal of background; The output of optical imaging system after the light splitting of RGB filter system in the imaging of area array CCD acquisition system; Wherein computer measurement selects different optical filter R, G, B from disposal system control RGB filter system, and gathers corresponding output signal V from area array CCD acquisition system _rb(i, j), V _gb(i, j), V _bb(i, j), i=1,2 ..., n, j=1,2 ..., m, m and n are CCD parameter in area array CCD acquisition system;

Step 4: the V that step 3 is obtained _rb(i, j), V _gb(i, j), V _bb(i, j) substitutes into colorimetry formula, obtains the color tristimulus values X of each pixel point of area array CCD _b(i, j), Y _b(i, j), Z _b(i, j), and by the lightness index W of following formulae discovery background _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *

$\left\{\begin{array}{c}{W}_b{(i,j)}^{*}=25Y_b{(i,j)}^{1/3}-17\\ U_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[u_b(i,j)-u_0]\\ V_b{(i,j)}^{*}=13W_b{(i,j)}^{*}\×[v_b(i,j)-v_0]\end{array}\right.$

Wherein:

$\left\{\begin{array}{c}{u}_b(i,j)=\frac{{4X}_b(i,j)}{X_b(i,j)+15Y_b(i,j)+{3Z}_b(i,j)}\\ v_b(i,j)=\frac{{6Y}_b(i,j)}{X_b(i,j)+15Y_b(i,j)+{3Z}_b(i,j)}\end{array}\right.$

Step 5: the lightness index W of the background that lightness index W (i, the j) * of the target obtained according to step 2 and chromaticity index U (i, j) *, V (i, j) * and step 4 obtain _b(i, j) * and chromaticity index U _b(i, j) *, V _b(i, j) *, calculates the colour contrast D (i, j) of target according to the following formula:

D(i,j)＝{[W(i,j) ^*-W _b(i,j) ^*] ²+[U(i,j) ^*-U _b(i,j) ^*] ²+[V(i,j) ^*-V _b(i,j) ^*] ²} ^1/2。