CN109947291A - Multiconductor recognition methods applied to optical touch screen - Google Patents
Multiconductor recognition methods applied to optical touch screen Download PDFInfo
- Publication number
- CN109947291A CN109947291A CN201910178320.9A CN201910178320A CN109947291A CN 109947291 A CN109947291 A CN 109947291A CN 201910178320 A CN201910178320 A CN 201910178320A CN 109947291 A CN109947291 A CN 109947291A
- Authority
- CN
- China
- Prior art keywords
- point
- touch screen
- touch
- coordinate
- image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Position Input By Displaying (AREA)
Abstract
The present invention is a kind of multiconductor recognition methods applied to optical touch screen, is related to image recognition and human-computer interaction technology.The present invention devises and obtains background image, contact position identifies, control mode touch mode differentiates, removal is put in vacation, coordinate is converted, the concrete methods of realizing of gamma correction part.This method can adjust automatically illumination LED brightness, background image is automatically saved, thus the variation of adaptive ambient enviroment.Vacation point minimizing technology can effectively remove false point in the case where not adding hardware, have low-cost advantage.Non-linear correction method can effectively eliminate the influence of optical imagery distortion, and the contact coordinate finally obtained is accurate.
Description
Technical field
The present invention relates to image recognition and field of human-computer interaction more particularly to a kind of more touchings applied to optical touch screen
Point recognition methods.
Background technique
With popularizing for computer, information is collected using computer, shows that achievement has become a kind of fashion.Optical touch screen is made
For a kind of updated plan different from existing capacitor, resistance and the touching techniques such as infrared, large scale easy to use with its is answered
With, reaction speed it is fast, save the advantages that space, be becoming increasingly popular it.
Multi-point touch mode refers to carries out multiple spot or the interactive operation of multi-user on single display circle song, has abandoned key
The single-point mode of operation of disk, mouse.User can be carried out single-touch by both hands and click, double-clicks, translates, rolls and rotate
Screen is touched etc. different gestures, realizes manipulation of following one's bent.
Due to the continuous development of touching technique, the disadvantage of optical touch screen is also gradually become prominent, most apparent defect
It is the presence of false point, so the inhibition that false point is added must be taken into consideration in method, to improve the accuracy rate of contact identification.
Summary of the invention
The present invention proposes that one kind can effectively remove false point, the multiconductor suitable for optical touch screen with more pinpoint accuracy
Recognition methods.
The present invention is the multiconductor recognition methods for optical touch screen, is broadly divided into following six part: (1) obtaining back
Scape image；(2) contact position identifies；(3) control mode touch mode judges；(4) the false point removal of two point mode；(5) coordinate is converted；(6)
Gamma correction.
Obtaining background image, the specific implementation steps are as follows:
Step 1: the image of touch screen surface is obtained by installing imaging sensor on the touchscreen；
Step 2: calculating the mean value of surface image gray scale in step 1；
Step 3: according to the brightness of the mean value adjustment LED illumination lamp of gray scale in step 2；
Step 4: background image and the preservation of touch screen surface are obtained by the imaging sensor of touch screen；
The specific implementation steps are as follows for contact position identification:
Step 5: the touch image of touch screen surface is obtained by the imaging sensor of touch screen；
Step 6: subtracting the touch image in step 5 with the background image in step 4 and obtain the part of image change；
Step 7: filtered image is obtained using gaussian filtering to the part changed in step 6；
Step 8: calculating the position of touch point and the radius of touch point according to image filtered in step 7；
The specific implementation steps are as follows for control mode touch mode judgement:
Step 9: this touch point number is determined according to the number of contact in step 8；
Step 10: 5 frame data of continuous acquisition judge 1 contact or 2 contact frame numbers in 5 frames according to step 9, judge into
The control mode touch mode entered；
The specific implementation steps are as follows for the removal of vacation point:
Step 11: after entering two point control mode touch mode, the radius of the contact recognized in step 8 being carried out descending
Sequence；
Step 12: the biggish point of the radius that left side camera recognizes correspond to the coordinate value that recognizes of right side camera compared with
Small point, the biggish point of the radius that right side camera recognizes correspond to the lesser point of coordinate value that left side camera recognizes；
The coordinate that touch point is determined according to above-mentioned rule, by the false point removal in the touch point recognized in step 8；
The specific implementation steps are as follows for coordinate conversion:
Step 13: according to formulaBy the position coordinates or step of the touch point under one-site model
Coordinate transformation in rapid 12 is angle coordinate；
Step 14: according to formulaBy the angle coordinate conversion in step 13
For cartesian coordinate；
The specific implementation steps are as follows for non-linear correction:
Step 15: bringing the cartesian coordinate in step 14 into formulaIt obtains
Final touch coordinate.
The invention has the following beneficial effects:
The invention proposes a kind of multiconductor recognition methods suitable for optical touch screen, have the advantages that
1, touch image information is obtained due to the method using difference, so the ring of different brightness can be adapted to automatically
Border.
2, every time booting operation when save initial background image, can the deformation of adaptable touch screen outline border and touch screen it is attached
The variation of near-ambient.
3, false point is eliminated using radius ranking method, is not required to addition additional hardware, there is advantage at low cost.
4, non-linear correction method can effectively eliminate the influence of camera distortion, and contact coordinate is accurate.
Detailed description of the invention
Fig. 1 is the structure of optical touch screen；
Fig. 2 is optical touch screen multiconductor recognition methods flow chart；
Fig. 3 is optical touch screen multiple point touching schematic diagram；
Fig. 4 is the coordinate system where coordinates computed point；
The modified-image obtained when Fig. 5 is single-touch by camera；
Fig. 6 is the modified-image obtained when two point touches by camera.
Specific embodiment
In order to enable those skilled in the art to better understand the present invention, come with reference to the accompanying drawing to the technology in the present invention
Scheme carries out clear, complete description explanation, it should be understood that these embodiments are merely to illustrate the specific reality of technical solution of the present invention
Mode is applied, rather than is limited the scope of the invention.After the present invention has been read, those skilled in the art are to of the invention each
The modification and replacement of kind equivalent form fall within protection scope defined by the claim of this application.
1, optical touch screen framework
Fig. 1 is the primary structure of optical touch screen, including controller, and camera and LED, reflective strip form.Two are taken the photograph
As head is separately mounted to the upper left corner, the upper right corner, in vertical direction with 45 ° of direction reflective strip directions, reflective strip issues LED
Light is reflected back camera.When a touch is present, meeting shield portions are reflected back the light of camera, are formed and touch image, pass through
Handling this image can recognize the position touched.
2, multiconductor recognition methods process
The multiconductor recognition methods of optical touch screen, is broadly divided into following six part: (1) obtaining background image；(2)
Contact position identification；(3) control mode touch mode judges；(4) the false point removal of two point mode；(5) coordinate is converted；(6) gamma correction.
Flow chart is as shown in Figure 2.
3, background image obtains
In the case where no touch point, the image obtained from camera is background image.In order to give following identification side
Method provides clearly background image and touches image, it is necessary to adjust the brightness of LED.LED luminance is divided into 16 grades.It is first that LED is bright
Degree is set as minimum, obtains background image at this time from camera, the gray average of background image is calculated, if this gray average is low
In preset threshold value, then 1 grade of LED luminance is improved, repeated from background image is obtained to the step of improving 1 grade of LED brightness, until
Background image gray average is higher than threshold value.LED luminance adjustment at this time finishes, and is at this moment final from the image that camera obtains
Background image saves this background image for subsequent use.Hereafter illumination LED brightness need not change again.
4, contact position identifies
When there is touch point to press, the contact situation of touch screen is as shown in figure 3, by taking touch point is at A as an example.At this point, from
The image that camera obtains is to touch image.The part of image change, such as Fig. 5 can be obtained by subtracting touch image with background image
It is shown.Since blackspot has occurred in blocking for finger, the position at blackspot center is the position touched.Remember blackspot center away from image most
Left side is m pixel, remembers the long n-pixel of image, then according to formula
Calculate to obtain the angle value α away from left frame at A point.A is calculated to obtain according to the method for calculating α by right side camera image
Angle value β of the point away from upper side frame.
The radius r of blackspot is blackspot right margin coordinate erIt subtracts the blackspot left side and meets coordinate el, i.e.,
R=er-el (2)
5, false point removal
When there is multiple touch points, by taking two o'clock as an example, touch point is A point and D point.Left side camera and right side camera are equal
Generate two blackspots as shown in FIG. 6.By above-mentioned contact position recognition methods, angle of two contacts away from left frame can be calculated
Spend α1, α2, the angle beta away from upper side frame1, β2.Then generate 22=4 touch point combinatorial coordinates A (α1, β1), B (α2, β1), C (α1,
β2), D (α2, β2).Two touch points produce four kinds of combinatorial coordinates at this time, need to remove false point.
The size of note left side two blackspot of camera is r1, r2.The radius of contact is carried out to descending sequence, obtains r1>
r2, the lesser point of coordinate value that the biggish point of the radius that left side camera recognizes is recognized corresponding to right side camera, according to
The corresponding relationship that above-mentioned regularity summarization goes out is as follows:
α1→r1→β1
α2→r2→β2
Coordinate after false point must be removed is A (α1, β1), D (α2, β2)。
6, coordinate is converted
Angle coordinate can not need to be converted to cartesian coordinate directly by using by angle coordinate (α, β).Angle coordinate is brought into
Formula
Normalized cartesian coordinate (x, y) can be obtained, using the linear distance L between two cameras as unit 1, such as scheme
Shown in 3.Using straight line determined by two cameras as x-axis, with perpendicular to x-axis, the straight line for crossing two camera line midpoints is y-axis
Coordinate system is constituted, as shown in Figure 4.
Gamma correction part is accomplished by the present invention
It distorts since camera exists, so that there are errors for the cartesian coordinate calculated.Bring cartesian coordinate into public affairs
Formula
Cartesian coordinate (X, Y) after correction can be obtained.This coordinate be still it is normalized, with straight between two cameras
Linear distance L is unit 1, as shown in Figure 3.
Wherein parameter ax, bx, cx, by, cyIt is demarcated by actual measurement.In the coordinate P that n determines1(X1, Y1), P2(X2, Y2), P3
(X3, Y3) ..., Pn(Xn, Yn) at successively press, pass through following four methods: (1) obtain background image；(2) contact position is known
Not；(3) false point removal；(4) coordinate is converted；Coordinate before successively measuring correction is Q1(x1, y1), Q2(x2, y2), Q3(x3,
y3) ..., Qn(xn, yn)。
By least square method, bringing following formula (5) into can calculate to correct the parameter of formula.
。
Claims (7)
1. a kind of adaptive multiconductor recognition methods for optical touch screen, which is characterized in that this method is divided into following six
Step:
A) background image is obtained；
B) contact position identifies；
C) control mode touch mode judges；
D) the false point removal of two point mode；
E) coordinate is converted；
F) gamma correction.
2. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
The detailed process of the step a) are as follows:
Firstly, obtaining the image of touch screen surface by the imaging sensor of installation on the touchscreen；
Secondly, the mean value of gauging surface image grayscale；
Again, the brightness of LED illumination lamp is adjusted according to the mean value of gray scale；
Finally, obtaining the background image of touch screen surface by the imaging sensor of touch screen and protecting row.
3. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
The detailed process of the step b) are as follows:
Firstly, obtaining the touch image of touch screen surface by the imaging sensor of touch screen；
Secondly, subtracting the touch image saved with the background image newly obtained, the part of image change is obtained；
Again, filtered image is obtained using gaussian filtering to the part of variation；
Finally, calculating quantity, position and the radius of touch point according to filtered image.
4. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
The detailed process of the step c) are as follows:
5 frame data of continuous acquisition judge 1 contact or 2 contact frame numbers in 5 frames according to step b), judge the touch-control mould entered
Formula；If 1 contact, then enter single-point touch, otherwise enters two point touch-control.
5. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
The detailed process of the step d) are as follows:
Firstly, if into two point control mode touch mode, to the contact radius recognized in step b), descending sequence；
Then, it is lesser that the biggish point of the radius that left side camera recognizes corresponds to the coordinate value that right side camera recognizes
Point, the biggish point of the radius that right side camera recognizes correspond to the lesser point of coordinate value that left side camera recognizes；According to
Above-mentioned rule determines the coordinate of touch point, by the false point removal in the touch point recognized in step b).
6. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
The specific practice of the step e) are as follows:
According to formulaBy the coordinate in the position coordinates of the touch point under one-site model or step d)
It is converted into angle coordinate；Then, according to formulaFlute card is converted by angle coordinate
That coordinate.
7. a kind of adaptive multiconductor recognition methods for optical touch screen according to claim 1, which is characterized in that
In the step f), pass through formulaY=byy+cyConvert cartesian coordinate, eliminate optical imagery when
Distortion, obtains final accurate touch coordinate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910178320.9A CN109947291A (en) | 2019-03-08 | 2019-03-08 | Multiconductor recognition methods applied to optical touch screen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910178320.9A CN109947291A (en) | 2019-03-08 | 2019-03-08 | Multiconductor recognition methods applied to optical touch screen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109947291A true CN109947291A (en) | 2019-06-28 |
Family
ID=67009440
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910178320.9A Withdrawn CN109947291A (en) | 2019-03-08 | 2019-03-08 | Multiconductor recognition methods applied to optical touch screen |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109947291A (en) |
-
2019
- 2019-03-08 CN CN201910178320.9A patent/CN109947291A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9262016B2 (en) | Gesture recognition method and interactive input system employing same | |
| JP5991041B2 (en) | Virtual touch screen system and bidirectional mode automatic switching method | |
| EP2713251A2 (en) | Method and electronic device for virtual handwritten input | |
| JP5802247B2 (en) | Information processing device | |
| US20130057515A1 (en) | Depth camera as a touch sensor | |
| CN108596955A (en) | A kind of image detecting method, image detection device and mobile terminal | |
| CN109782962A (en) | A kind of projection interactive method, device, system and terminal device | |
| CN108846371A (en) | Display device and fingerprint identification method thereof | |
| CN106293260B (en) | Optical touch device and sensing method thereof | |
| TW201820087A (en) | Touching method | |
| CN103019478B (en) | The contactor control device and the touch control detecting method that show based on curved surface | |
| CN109947291A (en) | Multiconductor recognition methods applied to optical touch screen | |
| KR20090061213A (en) | Complementary metal oxide semiconductor, source of light using the touch coordinates preception method and the touch screen system | |
| CN105912173B (en) | A kind of adaptive 3 recognition methods suitable for optical touch panel | |
| US20140253438A1 (en) | Input command based on hand gesture | |
| CN104571729A (en) | Multiple contact identification method applied to optical touch screen | |
| CN102479002B (en) | Optical touch control system and sensing method thereof | |
| Kim et al. | Method for user interface of large displays using arm pointing and finger counting gesture recognition | |
| CN112306353B (en) | Augmented reality device and interaction method thereof | |
| CN201859424U (en) | Touch control system of display | |
| CN110569799A (en) | Fingerprint module displacement detection method and device and terminal equipment | |
| CN105528086A (en) | Virtual keyboard input device and input method thereof | |
| EP4258090B1 (en) | Calibration method for an electronic display screen for touchless gesture control | |
| CN102520830A (en) | Virtual touch screen system based on image processing technology | |
| CN202404557U (en) | Virtual touch screen system based on image processing technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20190628 |
|
| WW01 | Invention patent application withdrawn after publication |