CN102507565B - Method for searching reaction color development area of immunochromatographic strip - Google Patents

Abstract

The invention discloses a method for searching a reaction color development area of an immunochromatographic strip. The method is characterized by including the steps: acquiring a total image of the immunochromatographic strip by an image acquisition device; forming a virtual rectangular image frame by using a computer; searching an upper edge line and a lower edge line of a reaction area; measuring the distance between the upper edge line and the lower edge line; acquiring a short central line b parallel to a short edge in the image frame and searching a reaction color development reference line; and searching a test line, acquiring peak data of the test line and determining a color development characteristic area of the test line. The method has the remarkably advantage of capability ofaccurately, rapidly, reliably and automatically capturing the reaction color development area of the immunochromatographic strip in the image of the immunochromatographic strip.

Description

A kind of immunity-chromatography test strip reaction solution local range search method

Technical field

The invention belongs to based on machine vision immunity-chromatography test strip technical field of measurement and test, concrete is a kind of immunity-chromatography test strip reaction solution local range search method.

Technical background

Modern immunologic assay technology comes from the development of labelling technique.The nineteen forty-one Coons etc. of continuing has founded since the fluorescein labelled antibody technology (fIuoreseent antiboay teeh-nique), eighties of last century beginning of the sixties at the end of the fifties, Yalaw etc. have founded radiommunoassay (radlol Jnmunoass3y, RIA) technology, South America state in 1966 and French scholar again simultaneously report set up enzyme immunoassay technique (enzyme im-Munoassay, EIA), comprise: the enzyme immunohistochemistry technique, solid-phase enzyme immunoassay is (such as ELISA, westenl blotting) and homogeneous EIA (claim again enzyme multiplied immunoassay technique, EMIT).Another conventional tag technology is that the colloid gold label immunoassay starts from eighties of last century eighties, except being applied to immuno-electron microscope, is widely used in immunity percolation and immunity-chromatography test.In addition, in succession report again at present and set up some novel markings immunological techniques, such as the rubidium marking immunoassays, nucleic acid marking immunoassays and quantum dot-labeled immunoassay.Some is widely used the experimental technique of these derives from technology in the clinical immunology check, and some still is in research and exploratory stage.Immune chromatograph testing method with the advantage such as quick, reliable, easy and simple to handle, that price is low is should develop rapidly aspect clinical diagnosis in recent years, now has been widely used in the fields such as clinical diagnosis, food safety detection, environment measuring.

Principle of work: when drop to be tested was added on the immunochromatography reaction test bar, test solution was by the capillary action of absorbing membrane on the immunochromatography reaction test bar, and taking collaurum to absorption has on the test reaction line of antibody.If the antigen in the test solution therewith antibody is corresponding, then produce the specific binding collaurum and be trapped on the test reaction line, take on a red color or aubergine, the depth of color is corresponding with the concentration of tested sample.

Only depend at present range estimation that the immune chromatograph testing result is qualitatively judged, when very slight color or obscure boundary Chu, range estimation is judged test result with regard to being difficult to, and can not express with quantification, and range of application is very limited.Studies show that, the concentration significant correlation of the depth of p-wire color and test fluid, can set up the statistical function relation according to the gray-scale value of p-wire or the concentration of color component and test fluid, obtain corresponding test fluid concentration by gray-scale value or color component, provide the index of quantification, finish the qualitative transformation to quantizing of test result.How to obtain gray-scale value or color component, a kind of is to utilize the sensors such as photodiode, light transmitting fiber to obtain, and this method has had ripe application on the checkout equipments such as urine.But the chemical detection such as immunochromatography and urine method has a great difference in principle, obtain p-wire can not show a candle to chemical detection develop the color like that deeply, neat, evenly, the edge of judgement p-wire need to lead to algorithm to be realized, brings very large difficulty for the quantification of test result.Another method is by image devices such as CCD, CMOS, by the sensed data of these imaging original papers is processed, obtains the gray-scale value of p-wire, is similar to general image and processes.These two kinds of methods are all higher to Lighting Design, manufacturing accuracy and the software and hardware facilities requirement of equipment and instrument, improved manufacturing cost, limited popularization, and existing not yet report.By image process to immunochromatography as a result sentence read result domestic yet there are no openly of method of expressing with quantification report for work.

We propose as a result interpretation method of a kind of immunochromatography based on machine vision, obtain the color component of p-wire by the method for image processing, according to digital image processing techniques and apery vision technique, in conjunction with the background modeling technology, weed out the noise in burr, flaw and the image forming course in the biological test paper image; Accurately extract chromogenic line position, immune chromatograph testing district and width, determine the size of test section chromogenic line colour developing information entropy, and set up the significant correlation funtcional relationship with standard color card, the colour developing depth to the test section chromogenic line is expressed with quantification, has realized that the quantification of as a result interpretation of immunochromatography detects.

Wherein, how to obtain and accurately capture immunity-chromatography test strip reaction solution zone in the immunity-chromatography test strip image, be based on the key of the as a result interpretation technology of immunochromatography of machine vision, only carrying out Image Information Processing in the immunity-chromatography test strip reaction solution zone accurately and reliably, the accuracy of guarantee sentence read result.

Summary of the invention

The purpose of this invention is to provide a kind of immunity-chromatography test strip reaction solution local range search method, can accurately and reliably capture immunity-chromatography test strip reaction solution zone in the immunity-chromatography test strip image.

For achieving the above object, the present invention explains a kind of immunity-chromatography test strip reaction solution local range search method, and its key is to carry out according to the following steps:

Step 1: utilize the global image of image collecting device collection immunity-chromatography test strip, and this global image is kept in the computing machine;

Step 2: according to the frames images of the virtual rectangle of color development area information of prior setting, the length of this frames images and wide respectively greater than the length in reaction solution district on the described immunity-chromatography test strip and wide;

Step 3: obtain long center line parallel with long limit in the frames images, and the coboundary line in search reaction solution district, the top from this long center line to frames images;

If in frames images, find the coboundary line, judge then whether the coboundary line is parallel with long center line, if not parallel, then adjust the angle of described frames images and long center line, make the coboundary line parallel with long center line, and calculate distance between coboundary line and the long center line, again the lower limb line in the search of the below from described long center line to frames images reaction solution district;

If then in frames images, do not find the coboundary line, the first lower limb line in the below from described long center line to frames images search reaction solution district then, judge again whether the lower limb line is parallel with long center line, if not parallel, then adjust the angle of frames images and long center line, make the lower limb line parallel with long center line, and calculate the distance between lower limb line and the long center line, again the coboundary line in the search of the top from described long center line to frames images reaction solution district;

Step 4: measure the distance between coboundary line and the lower limb line, adjust the position of frames images, make long center line be positioned at the centre of coboundary line and lower limb line and parallel with the two;

Step 5: obtain short central line parallel with minor face in the frames images, and from the right-hand search reaction solution reference line of this short central alignment frames images;

If in right-hand frames images, search the reaction solution reference line, then in the specified scope in described reaction solution reference line left side, search for p-wire, and obtain the peak-data of p-wire, determine the color feature zone of p-wire;

If in right-hand frames images, do not search the reaction solution reference line, then search for the reaction solution reference line from the left of described short central alignment frames images, after in the left frames images, searching the reaction solution reference line, in the specified scope on described reaction solution reference line right side, search for p-wire again, and obtain the peak-data of p-wire, determine the color feature zone of p-wire.

The searching method of reaction solution reference line is described in the searching method of the line of coboundary described in the step 3 and the step 5: analyze the upper lower limb in immunity-chromatography test strip reaction solution zone as can be known, one, the color characteristic of upper lower limb is changed significantly, and namely local edge is apparent in view; Two, the gradient direction of upper lower limb almost is and the horizontal direction parallel of image that the gradient direction that namely is in the pixel at edge is in 90 ± ε.Therefore, the edge detection operator (Sobel, Canny, Prewitt, Roberts etc.) of selecting to be fit to is gone to edge amplitude and the edge direction angle of detected image.Take the Canny edge detection algorithm as example:

x i-1j-1	x i-1j	x i-1j+1
			x ij-1	x ij	x ij+1
x i+1j-1	x ij+1	x i+1j+1

Then the Canny algorithm in the gradient of x direction is:

dx(i，j)＝((x _i+1j+1-x _i+1j)+(x _ij+x-x _ij))/2 (1)

Gradient in the y direction is:

dy(i，j)＝((x _i+1j+1-x _ij+1)+(x _i+1j-x _ij))/2 (2)

The gradient magnitude of locating at pixel (x, y) is:

$d(i,j)=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="dx"\; filenames="HSA00000624825300011.png"\; state="\{\{state\}\}">dx</figure-callout>}}^2+{\mathrm{dy}}^2}---\left(3\right)$

The gradient direction of locating at pixel (x, y) is:

θ(i，j)＝arctan(dy/dx) (4)

According to above-mentioned formula and the specificity analysis of edge line distribution correlation up and down: concrete processing procedure is as follows: according to formula 3 and 4 respectively compute gradient value and gradient direction values.According to 90 ± ε restriction of edge direction, each pixel in the image of the overall situation is processed:

$d\_\mathrm{mod}\mathrm{ify}(i,j)=\left\{\begin{array}{cc}0& \mathrm{if}\left(\right|\mathrm{\&theta;}|<10)\\ d& \mathrm{else}\end{array}\right.----\left(5\right)$

Then, according to newly-generated edge magnitude image d_modify, with the edge amplitude of image to the y direction projection, that is:

$f\left(i\right)=\underset{j=0}{\overset{\mathrm{bi}.\mathrm{width}}{\mathrm{\&Sigma;}}}d\_\mathrm{mod}\mathrm{ify}(i,j)---\left(6\right)$

Bi.width in 6 formulas is the width of image, is edge in y value corresponding to overall maximizing ₁, then shield this zone, then seek again time maximal value, be edge ₂Ask for edge ₁With edge ₂One of middle maximum as lower limb, certainly, and a minimum boundary value as coboundary.

At last, get the folded intermediate image in edge and turn clockwise 90 according to above-mentioned same step, the latter half of image is sought the left and right edges of reference line after rotation.

In the step 5, described specified scope is 300～500mm.

Remarkable result of the present invention is: a kind of immunity-chromatography test strip reaction solution local range search method is provided, and can be accurately, automatic capturing immunity-chromatography test strip reaction solution zone in the immunity-chromatography test strip image quickly and reliably.

Description of drawings

Fig. 1 is immunity-chromatography test strip reaction solution area schematic;

Fig. 2 is process flow diagram of the present invention.

Embodiment

The below is described in further detail the present invention with regard to specific embodiment.

As shown in Figure 2: a kind of immunity-chromatography test strip reaction solution local range search method, its key is to carry out according to the following steps:

Step 1: utilize the global image of image collecting device collection immunity-chromatography test strip, and this global image is kept in the computing machine;

Step 2: according to the frames images A of the virtual rectangle of color development area information of prior setting, the length of this frames images A and wide respectively greater than the length of reaction solution district B on the immunity-chromatography test strip and wide;

Step 3: obtain long center line a parallel with long limit among the frames images A, and the coboundary line S1 of the search of the top from this long center line a to frames images A reaction solution district B;

If in frames images A, find coboundary line S1, judge then whether coboundary line S1 is parallel with long center line a, if not parallel, then adjust the angle of described frames images A and long center line a, make coboundary line S1 parallel with long center line a, and calculate distance between coboundary line S1 and the long center line a, again the lower limb line S2 of the search of the below from described long center line a to frames images A reaction solution district B;

If then in frames images A, do not find coboundary line s1, the first lower limb line S2 of the below from described long center line a to frames images A search reaction solution district B then, judge again whether lower limb line S2 is parallel with long center line a, if not parallel, then adjust the angle of frames images A and long center line a, make lower limb line S2 parallel with long center line a, and calculate distance between lower limb line S2 and the long center line a, again the coboundary line S1 of the search of the top from described long center line a to frames images A reaction solution district B;

Step 4: measure the distance between coboundary line S1 and the lower limb line S2, adjust the position of frames images A, make long center line a be positioned at the centre of coboundary line S1 and lower limb line S2 and parallel with the two;

Step 5: obtain short central line b parallel with minor face among the frames images A, and the right-hand search reaction solution reference line C from this short central line b to frames images A;

If in right-hand frames images A, search the reaction solution reference line C, then in the specified scope in described reaction solution reference line C left side, search for p-wire D, and obtain the peak-data of p-wire D, determine the color feature zone of p-wire D;

If in right-hand frames images A, do not search the reaction solution reference line C, then the left from described short central line b to frames images A is searched for the reaction solution reference line C, after in left frames images A, searching the reaction solution reference line C, in the specified scope on described reaction solution reference line C right side, search for again p-wire D, and obtain the peak-data of p-wire D, determine the color feature zone of p-wire D.

The searching method of reaction solution reference line C is described in the searching method of the line of coboundary described in step 3 S1 and the step 5: as shown in Figure 1, analyze the upper lower limb in immunity-chromatography test strip reaction solution zone as can be known, one, the color characteristic of upper lower limb is changed significantly, and namely local edge is apparent in view; Two, the gradient direction of upper lower limb almost is and the horizontal direction parallel of image that the gradient direction that namely is in the pixel at edge is in 90 ± ε.Therefore, the edge detection operator with selecting to be fit to such as Sobel, Canny, Prewitt, Roberts etc., goes to edge amplitude and the edge direction angle of detected image.Take the Canny edge detection algorithm as example:

x i-1j-1	x i- 1j	x i-1j+1
			x ij-1	x ij	x ij+1
x i+1j-1	x ij+1	x i+1j+1

Then the Canny algorithm in the gradient of x direction is:

dx(i，j)＝((x _i+1j+1-x _i+1j)+(x _ij+1-x _ij))/2 (1)

Gradient in the y direction is:

Dy (i, j)=((x _I+1j+1-x _Ij+1) ten (x _I+1j-x _Ij))/2 (2)

The gradient magnitude of locating at pixel (x, y) is:

$d(i,j)=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="dx"\; filenames="HSA00000624825300011.png"\; state="\{\{state\}\}">dx</figure-callout>}}^2+{\mathrm{dy}}^2}---\left(3\right)$

The gradient direction of locating at pixel (x, y) is:

θ(i，j)＝arctan(dy/dx) (4)

According to above-mentioned formula and the specificity analysis of edge line distribution correlation up and down: concrete processing procedure is as follows: according to formula 3 and 4 respectively compute gradient value and gradient direction values.According to 90 ± ε restriction of edge direction, each pixel in the image of the overall situation is processed:

$d\_\mathrm{mod}\mathrm{ify}(i,j)=\left\{\begin{array}{cc}0& \mathrm{if}\left(\right|\mathrm{\&theta;}|<10)\\ d& \mathrm{else}\end{array}\right.----\left(5\right)$

Then, according to newly-generated edge magnitude image d_modify, with the edge amplitude of image to the y direction projection, that is:

$f\left(i\right)=\underset{j=0}{\overset{\mathrm{bi}.\mathrm{width}}{\mathrm{\&Sigma;}}}d\_\mathrm{mod}\mathrm{ify}(i,j)---\left(6\right)$

(6) bi.width in the formula is the width of image, is edge in y value corresponding to overall maximizing ₁, then shield this zone, then seek again time maximal value, be edge ₂Ask for edge ₁With edge ₂One of middle maximum as lower limb, certainly, and a minimum boundary value as coboundary.

At last, get the folded intermediate image in edge and turn clockwise 90.According to above-mentioned same step, the latter half of image is sought the left and right edges of reference line after rotation.

In the step 5, described specified scope is 300～500mm.

Claims (3)

1. immunity-chromatography test strip reaction solution local range search method is characterized in that carrying out according to the following steps:

Step 1: utilize the global image of image collecting device collection immunity-chromatography test strip, and this global image is kept in the computing machine;

Step 2: according to the frames images (A) of the virtual rectangle of color development area information of prior setting, the length of this frames images (A) and wide respectively greater than the length of reaction solution district (B) on the described immunity-chromatography test strip and wide;

Step 3: obtain long center line (a) parallel with long limit in the frames images (A), and search for the coboundary line (S1) in described reaction solution district (B) from this long center line (a) to the top of frames images (A);

If in frames images (A), find coboundary line (S1), judge then whether coboundary line (S1) is parallel with long center line (a), if not parallel, then adjust the angle of described frames images (A) and long center line (a), make coboundary line (S1) parallel with long center line (a), and calculate distance between coboundary line (S1) and the long center line (a), again the lower limb line (S2) in search reaction solution district, the below from described long center line (a) to frames images (A) (B);

If then in frames images (A), do not find coboundary line (S1), the lower limb line (S2) in the first below from described long center line (a) to frames images (A) search reaction solution district (B) then, judge again whether lower limb line (S2) is parallel with long center line (a), if not parallel, then adjust the angle of frames images (A) and long center line (a), make lower limb line (S2) parallel with long center line (a), and calculate distance between lower limb line (S2) and the long center line (a), again the coboundary line (S1) in search reaction solution district, the top from described long center line (a) to frames images (A) (B);

Step 4: measure the distance between coboundary line (S1) and the lower limb line (S2), adjust the position of frames images (A), make long center line (a) be positioned at the centre of coboundary line (S1) and lower limb line (S2) and parallel with the two;

Step 5: obtain short central line (b) parallel with minor face in the frames images (A), and the right-hand search reaction solution reference line (C) from this short central line (b) to frames images (A);

If in right-hand frames images (A), search reaction solution reference line (C), then in the specified scope in described reaction solution reference line (C) left side, search for p-wire (D), and obtain the peak-data of p-wire (D), determine the color feature zone of p-wire (D);

If in right-hand frames images (A), do not search reaction solution reference line (C), then the left from described short central line (b) to frames images (A) is searched for reaction solution reference line (C), after in left frames images (A), searching reaction solution reference line (C), in the specified scope on described reaction solution reference line (C) right side, search for again p-wire (D), and obtain the peak-data of p-wire (D), determine the color feature zone of p-wire (D).

2. a kind of immunity-chromatography test strip reaction solution local range search method according to claim 1, it is characterized in that, the searching method of reaction solution reference line (C) is described in the searching method of the line of coboundary described in the step 3 (S1) and the step 5: the gradient direction of demarcating the pixel that is in the edge is in 90 ± ε, utilize edge amplitude and the edge direction angle of edge detection operator detected image

The gradient of obtaining in the x direction is:

dx(i，j)＝((x _i+1j+1-x _i+1j)+(x _ij+1-x _ij))/2 (1)

Gradient in the y direction is:

dy(i，j)＝((x _i+1j+1-x _ij+1)+(x _i+1j-x _ij))/ ² ( ₂)

The gradient magnitude of locating at pixel (x, y) is:

The gradient direction of locating at pixel (x, y) is:

θ(i，j)＝arctan(dy/dx) (4)

Again according to formula (1), (2), (3), (4) and up and down the edge line distribution character analyze: concrete processing procedure is as follows: distinguish compute gradient value and gradient direction value according to formula (3) and (4), according to 90 ± ε restriction of edge direction, each pixel in the image of the overall situation is processed:

Then, according to newly-generated edge magnitude image d_modify, with the edge amplitude of image to the y direction projection, that is:

Bi.width in the formula (6) is the width of image, is edge in y value corresponding to overall maximizing ₁, then shield this zone, then seek again time maximal value, be edge ₂, ask for edge ₁With edge ₂One of middle maximum as lower limb, certainly, and a minimum boundary value as coboundary;

At last, get the folded intermediate image in edge and turn clockwise 90, according to above-mentioned same step, the latter half of image is sought the left and right edges of reference line after rotation.

3. a kind of immunity-chromatography test strip reaction solution local range search method according to claim 1 is characterized in that, in the step 5, described specified scope is 300～500mm.

Images