CN102243103A - Method for quickly measuring colors and three-dimensional profile of object - Google Patents

Abstract

The invention provides a method for quickly measuring colors and a three-dimensional profile of an object. The method comprises the following steps: establishing a reflective model of a colorful object; establishing measurement code fringes; separating measurement information; acquiring color information to obtain color three-dimensional information of the measured object; and finally acquiring three-dimensional profile information of the object. Since a code fringe projection method is adopted, only two projection code fringes are required to be collected, and the effects of high measurement accuracy and high measurement speed are achieved; meanwhile, since the color information and the profile information are acquired from the same image, no matching error exists. The method has the advantages of high measurement accuracy, small matching error and high measurement speed.

Description

The quick measuring method of a kind of object color and three-D profile

Technical field

The invention belongs to complex object three-D profile detection technique field, be specifically related to the quick measuring method of a kind of object color and three-D profile.

Background technology

At present; because the optical three-dimensional contour measuring technique has advantages such as noncontact, resolution height and data acquisition speed be fast; become one of heat subject of studying in the world in recent years, and be widely used in reverse engineering, industry detection automatically, new product development, medical diagnosis, cultural heritage protection and fields such as recovery and modern manufacturing system.Yet, when color models such as the protection of carrying out colored reverse engineering design, cultural heritage and scientific research analysis, the artwork and toy making are measured, shape and color are the fundamental elements of its measurement, shape is the three-D profile data of object under test, represents with the X in the world coordinate system, Y, Z coordinate figure usually; Color then characterizes the reflection characteristic of incident ray and the texture features of surfacing by body surface, adopts R, G, the three-dimensional absolute color information representation of B usually.How can obtain the accurate three-dimensional profile information of object, can obtain the absolute three-dimensional colouring information of object again, promptly high precision color three dimension profile measurement is the another big research focus in current profile measurement field.

The color three dimension contour measuring method, mostly be on the basis of optical three-dimensional contour measuring technique, carry out the coupling of volume coordinate with colouring information and finish, need carry out the collection of three-D profile information and three-dimensional colouring information respectively like this, thereby cause measuring speed slow, and matching error is big.At present, the color three dimension contour measuring method can be divided into two classes according to lighting system: a class is the vision measuring method of passive type, it is the lighting system that adopts non-structured light, obtain two-dimensional image from one or more angles, obtain three-dimensional shape data by a series of complex image processing algorithms, be X, Y, the Z D coordinates value, simultaneously, can obtain a planar coloured image by a color observation system, it includes R, G, the B colouring information, in conjunction with the system calibrating value of carrying out in advance, the data of twice acquisition are carried out the space coupling, can obtain the color three dimension profile (X of object, Y, Z-R, G, B).The measurement of this method must depend on condition precedents such as object form, illumination condition, and it not only needs to carry out the lot of data computing, and measuring accuracy is lower, and matching error is big; Another kind of is the active measuring method that is more suitable in metering, it is the measuring method that adopts line-structured light scanning, be meant with a line-structured light from a directional lighting object, because body surface is to the space or the time modulation of light field, observe from different directions, obtain the deformed configurations light image, these distortion corresponding the elevation information of object, just can calculate the appearance profile of object in conjunction with trigonometry, be X, Y, the Z D coordinates value then, obtains the colouring information of object under non-structure optical illumination situation, carry out the coupling of shape and color at last, obtain the color three dimension information of object.The measuring speed of this method is slow, and has big matching error.

Summary of the invention

In order to overcome the shortcoming of above-mentioned prior art, the object of the present invention is to provide the quick measuring method of a kind of object color and three-D profile, it is higher to have measuring accuracy, and matching error is little, the advantage that measuring speed is fast.

In order to achieve the above object, the technical scheme taked of the present invention is:

The quick measuring method of a kind of object color and three-D profile may further comprise the steps:

The first step is set up the reflection model of color body, supposes that the intensity of three color components of red, green, blue is respectively I _R, I _GAnd I _BThe coding projection striped can along continuous straight runs x or vertical direction y encode, also can encode along gray level direction z, with the coding projection fringe projection to tested color body, the mapping relations between coding projection striped and testee have been obtained thus, i.e. the reflection model of color body;

Second goes on foot, and sets up and measures strip encoding, adopts three color components of red, green, blue of color fringe to realize that three of strip encoding goes on foot phase shift, i.e. the light distribution I of three kinds of color components of red, green, blue _R, I _GAnd I _BBe respectively:

In the formula: I _mLargest light intensity for each component;

For each color component in point (x, the prima facies place value of y) locating;

The 3rd step, separating and measuring information, to measure strip encoding is projected on the testee, adopt ccd video camera to take then, obtain the deformation pattern that it is subjected to object color and highly modulates, suppose that testee is positioned at X-Y plane, its elevation information is on the Z direction, when the color of object caused strip encoding to change, what showed was the variation of Z direction R, each color component gray level of G, B; And because the variation of object height can cause strip encoding that horizontal translation takes place on directions X or Y direction, therefore, because the striped that color caused changes and is positioned on two different directions owing to highly caused striped changes, and in view of the above two parts information separated is come;

The 4th step, obtain colouring information, obtain changing the deformation information of the strip encoding that causes owing to object color by the 3rd step, set up the projected fringe of reflection model and the reflection mapping relations of object color in conjunction with the first step, according to the gray scale of each regional each color component of gained image of striped and throw relation between the striped color component gray scale, obtain the gray-scale value of each color component in each zone, testee surface, i.e. the color three-dimensional information of testee;

The 5th step, obtain three-D profile information, obtain three color components of red, green, blue being separated because object height changes the deformation information of the strip encoding cause by the 3rd step, be three step phase shifted images, the formula according to following three step phase shift algorithm obtains its phase information then

In the formula: I _R(x, y), I _G(x, y), I _B(x, (x, the light intensity value of y) locating according to the relation of the demarcation between phase value and the elevation information, are obtained the three-D profile information of object at some y) to represent each component of red, green, blue respectively.

Because the present invention adopts the method for strip encoding projection, only need to gather two width of cloth projection strip encodings, therefore, it is the measuring accuracy height not only, and measuring speed is fast, simultaneously, because colouring information and this two parts information of profile information all obtains from piece image, so there is not any matching error.

Embodiment

Below in conjunction with embodiment the present invention is done detailed description.

The quick measuring method of a kind of object color and three-D profile may further comprise the steps:

The first step, set up the reflection model of color body, because the colouring information of color body is subjected to the influence of factors such as angle of surfaceness, incident ray and the incidence point surface normal on wavelength, the light distribution of incident ray, surface to be measured, obtaining of the absolute color information of testee is extremely complicated, in order to obtain the absolute color information of testee, must set up suitable reflection model, in order to set up reflection model, first design coding projection striped, suppose three color components of red, green, blue intensity be respectively I _R, I _GAnd I _B, the coding projection striped can along continuous straight runs x or vertical direction y encode, also can encode along gray level direction z, if the coding projection striped along the x direction encoding, then the light intensity of its coding projection striped can be by I ₁, I ₂Or I ₃Three kinds of modes are encoded:

$I_1=\left\{\begin{array}{c}{I}_R=k_{1}x\\ I_G=0\\ I_B=0\end{array}\right.,$ $I_2=\left\{\begin{array}{c}{I}_R=0\\ I_G=k_{1}x\\ I_B=0\end{array}\right.$ With $I_3=\left\{\begin{array}{c}{I}_R=0\\ I_G=0\\ I_B=k_{1}x\end{array}\right.$

In the formula: k ₁Be the gray scales factor, and the coding projection striped also can be according to I ₁, I ₂And I ₃Array configuration encode; If the coding projection striped is encoded along gray level direction z, then the light intensity of its coding projection striped can by

With

Three kinds of modes are encoded:

$I_{k_{2}R}=\left\{\begin{array}{c}{I}_R=k_{2}z\\ I_G=0\\ I_B=0\end{array}\right.,$ $I_{k_{2}G}=\left\{\begin{array}{c}{I}_R=0\\ I_G=k_{1}z\\ I_B=0\end{array}\right.$ With $I_{k_{2}B}=\left\{\begin{array}{c}{I}_R=0\\ I_G=0\\ I_B=k_{2}z\end{array}\right.$

In the formula: k ₂Be the gray scales factor, and the coding projection striped also can according to

With

Array configuration encode, by projector with the coding projection fringe projection to testee, take the image that projects to the coding projection striped on the testee by ccd video camera, obtain the mapping relations of coding projection striped and testee by Flame Image Process, and carried out demarcating in conjunction with the distortion of the color of projector and ccd video camera and revised, obtain the mapping relations of coloud coding projected fringe and tested color body at last, i.e. the reflection model of color body;

Second step, set up and measure strip encoding, in order to carry out the synchro measure of color three dimension and profile three-dimensional, must carry out the design of auxiliaring coding striped, in order to guarantee the measurement of three-D profile, adopt three step phase shifts of three color components realizations of red, green, blue strip encoding in the coloured image, just there are fixing phase-shift phase respectively in light distribution IR, the IG of three kinds of color components of red, green, blue and IB:

In the formula: I _mLargest light intensity for each component;

For each color component in point (x, the prima facies place value of y) locating;

The 3rd step, separating and measuring information, to measure strip encoding is projected on the testee, adopt ccd video camera to take then, obtain the deformation pattern that it is subjected to object color and highly modulates, suppose that testee is positioned at X-Y plane, its elevation information is on the Z direction, when the color of object causes strip encoding to change, what showed is the variation of Z direction R, each color component gray level of G, B, because the difference of object each several part color, the numerical value of caused each color component of measurement strip encoding also is not quite similar; And because the variation of object height can cause strip encoding that horizontal translation takes place on directions X or Y direction, therefore, because the striped that color caused changes and is positioned on two different directions owing to highly caused striped changes, and in view of the above two parts information separated is come;

The 4th step, obtain colouring information, obtain changing the deformation information of the strip encoding that causes owing to object color by the 3rd step, set up the projected fringe of reflection model and the reflection mapping relations of object color in conjunction with the first step, according to the gray scale of each regional each color component of gained image of striped and throw relation between the striped color component gray scale, obtain the gray-scale value of each color component in each zone, testee surface, i.e. the color three-dimensional information of testee;

The 5th step, obtain three-D profile information, obtain three color components of red, green, blue being separated because object height changes the deformation information of the strip encoding cause by the 3rd step, be three step phase shifted images, the formula according to following three step phase shift algorithm obtains its phase information then

In the formula: I _R(x, y), I _G(x, y), I _B(x, (x, the light intensity value of y) locating according to the relation of the demarcation between phase value and the elevation information, are obtained the three-D profile information of object at some y) to represent each component of red, green, blue respectively.

So far, the color three-dimensional information of object and height three-dimensional information have just all found the solution out.This method adopts the method for strip encoding projection, only need to gather two width of cloth projection strip encodings, therefore, it is the measuring accuracy height not only, and measuring speed is fast, simultaneously, because colouring information and this two parts information of profile information all obtains from piece image, so there is not any matching error.

Claims (1)

1. the quick measuring method of object color and three-D profile is characterized in that, may further comprise the steps:

The first step is set up the reflection model of color body, supposes that the intensity of three color components of red, green, blue is respectively I _R, I _GAnd I _BThe coding projection striped can along continuous straight runs x or vertical direction y encode, also can encode along gray level direction z, with the coding projection fringe projection to tested color body, the mapping relations between coding projection striped and testee have been obtained thus, i.e. the reflection model of color body;

Second goes on foot, and sets up and measures strip encoding, adopts three color components of red, green, blue of color fringe to realize that three of strip encoding goes on foot phase shift, i.e. the light distribution I of three kinds of color components of red, green, blue _R, I _GAnd I _BBe respectively:

In the formula: I _mLargest light intensity for each component; For each color component in point (x, the prima facies place value of y) locating;

The 3rd step, separating and measuring information, to measure strip encoding is projected on the testee, adopt ccd video camera to take then, obtain the deformation pattern that it is subjected to object color and highly modulates, suppose that testee is positioned at X-Y plane, its elevation information is on the Z direction, when the color of object caused strip encoding to change, what showed was the variation of Z direction R, each color component gray level of G, B; And because the variation of object height can cause strip encoding that horizontal translation takes place on directions X or Y direction, therefore, because the striped that color caused changes and is positioned on two different directions owing to highly caused striped changes, and in view of the above two parts information separated is come;

The 4th step, obtain colouring information, obtain changing the deformation information of the strip encoding that causes owing to object color by the 3rd step, set up the projected fringe of reflection model and the reflection mapping relations of object color in conjunction with the first step, according to the gray scale of each regional each color component of gained image of striped and throw relation between the striped color component gray scale, obtain the gray-scale value of each color component in each zone, testee surface, i.e. the color three-dimensional information of testee;

The 5th step, obtain three-D profile information, obtain three color components of red, green, blue being separated because object height changes the deformation information of the strip encoding cause by the 3rd step, be three step phase shifted images, the formula according to following three step phase shift algorithm obtains its phase information then

In the formula: I _R(x, y), I _G(x, y), I _B(x, (x, the light intensity value of y) locating according to the relation of the demarcation between phase value and the elevation information, are obtained the three-D profile information of object at some y) to represent each component of red, green, blue respectively.