A noise reduction method for interactive projection system

Abstract

The present invention relates to a noise reduction method for an interactive projection system. When the interactive projection system is used, a target touches a certain position on a screen, namely, the target position, and laser reflection forms a target bright spot and is presented on an image. A host obtains an image, locates the target position according to the target bright spot on the image, and executes a corresponding instruction. The method extracts the target bright spot by weight superposition based on a background difference method under an ambient light illumination. The method comprises: before the interactive projection system is used, a person is used as a reference, and the person stands in front of the screen and touches the screen; 1) adjusting the brightness and contrast of the camera to eliminate the human figure on the image and retain the bright spot formed by touching the screen; 2) adjusting the threshold and noise based on a Gaussian filtering algorithm to further eliminate the human figure on the image and retain the bright spot formed by touching the screen; 3) adjusting the enhancement and blur based on an enhancement algorithm to make the bright spot on the image clear. Eliminate or reduce the interference caused by sunlight.

Description

Technical Field

[0001] The invention relates to interactive projection technology, and in particular to a noise reduction method for an interactive projection system. Background Art

[0002] Interactive walls usually include wall displays and interactive sensing technology to provide interactive experience and display content. Interactive wall systems use interactive technology to sense user operations and actions. Common interactive technologies include optical touch, infrared touch, depth cameras, etc. Through these technologies, users can interact with projected content through touch, gestures or movements. Common interactive technologies have strict requirements on ambient light brightness. Generally, the indoor light brightness cannot exceed 100 lux, otherwise it will cause serious interference to the interactive system. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a noise reduction method for an interactive projection system.

[0004] The technical solution of the present invention:

[0005] A method for reducing noise in an interactive projection system, the interactive projection system comprising a projector, a laser generator, a camera, and a host, the host being connected to the camera and the projector, projecting an image on a wall, a floor, or a screen through the projector, and forming a laser light curtain on the image through the laser generator. When the interactive projection system is used, a target touches a certain position on the image, namely the target position, and laser reflection forms a target bright spot and is presented on an image captured by the camera, the host acquires the image, locates the target position according to the target bright spot, and executes corresponding instructions; the method extracts the target bright spot by weighted superposition based on the background difference method under an ambient light illumination;

[0006] Including: before the interactive projection system is used, a person is used as a reference, and the person stands in front of the screen and touches the screen;

[0007] 1) Adjust the brightness and contrast of the camera to eliminate the human figure on the image and retain the bright spots formed by touching the screen;

[0008] 2) Based on the Gaussian filtering algorithm, the threshold and noise are adjusted to further eliminate the human figure on the image and retain the bright spots formed by touching the screen;

[0009] 3) Based on the enhancement algorithm, adjust the enhancement and blur to make the highlights on the image clear.

[0010] The method further comprises: setting a maximum area and a minimum area of ​​a target bright spot, and extracting the target bright spot according to the size of the bright spot area on the image;

[0011] The maximum area of ​​the target bright spot is Smax, the minimum area of ​​the target bright spot is Smin, and the area of ​​a bright spot on the laser plane image is S;

[0012] If Smax≥S≥Smin, the bright spot is determined to be the target bright spot.

[0013] The laser wavelength is 808nm, and two layers of filters are installed on the camera, wherein the first layer filters 800-2500nm and the second layer filters 808nm.

[0014] The laser wavelength is 940nm, and two layers of filters are installed on the camera, wherein the first layer filters 800-2500nm and the second layer filters 940nm.

[0015] The advantages of the present invention are reasonable design, ingenious conception, ability to accurately extract target bright spots, eliminate or reduce interference caused by sunlight, and enable the interactive projection system to operate normally when the ambient light illumination does not exceed 500 lux. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the interactive projection system structure.

[0017] Figure 2 It is a noise reduction flow chart of the interactive projection system.

[0018] In the figure, there is a projector 1, a laser generator 2, a camera 3, a host 4, a screen 5, a laser light curtain 6, a target 7, a filter 8, and a filter 9. DETAILED DESCRIPTION

[0019] like Figure 1 As shown, an interactive projection system includes a projector 1, a laser generator 2, a camera 3, and a host. The host 4 is connected to the camera 3 and the projector 1. A picture 5 is projected on the wall through the projector 1. A laser light curtain 6 is formed on the picture through the laser generator 2. The camera 3 collects images. The target 7 touches a certain position on the picture 5, namely the target position. The laser is reflected to form a target bright spot and is presented on the image. The host 4 obtains the image, locates the target position according to the target bright spot position, and executes corresponding instructions. The laser wavelength is 808nm. The camera 3 is installed with filters 8 and 9, wherein the first layer filters 800-2500nm and the second layer filters 808nm.

[0020] like Figure 2 As shown, the above-mentioned interactive projection system noise reduction method extracts the target bright spot by weighted superposition based on the background difference method under an ambient light illumination;

[0021] include:

[0022] Step 1: Take a person as a reference, stand in front of the picture and touch the picture;

[0023] 1) Adjust the brightness and contrast of the camera to eliminate the human figure on the image and retain the bright spots formed by touching the screen;

[0024] 2) Based on the Gaussian filtering algorithm, adjust the threshold and noise to eliminate the human figure on the image and retain the bright spots formed by touching the screen;

[0025] 3) Based on the enhancement algorithm, adjust the enhancement and blur to make the bright spots on the image clear;

[0026] Step 2: Background subtraction method to extract target highlights;

[0027] Step 3: Set the maximum area and minimum area of ​​the target, and extract the target bright spots according to the bright spot area on the image;

[0028] The maximum area of ​​the target is Smax, the minimum area of ​​the target bright spot is Smin, and the area of ​​a bright spot on the laser plane image is S;

[0029] If Smax≥S≥Smin, the bright spot is determined to be the target bright spot.

[0030] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for reducing noise in an interactive projection system, the interactive projection system comprising a projector, a laser generator, a camera, and a host, the host being connected to the camera and the projector, projecting an image on a wall, a floor, or a screen through the projector, and forming a laser light curtain on the image through the laser generator. When the interactive projection system is used, a target touches a certain position on the image, namely the target position, and the laser is reflected to form a target bright spot and present on the image, and the host acquires the image, locates the target position according to the target bright spot, and executes corresponding instructions; characterized in that: The method, under a certain ambient light illumination, obtains the initial frame picture and the next frame picture of the image based on the background difference method, and extracts the target bright spot by weighted superposition of the initial frame picture and the next frame picture of the image; Including: before the interactive projection system is used, a person is used as a reference, and the person stands in front of the screen and touches the screen; 1) Adjust the brightness and contrast of the camera to eliminate the human figure on the image and retain the bright spots formed by touching the screen; 2) Based on the Gaussian filtering algorithm, the threshold and noise are adjusted to further eliminate the human figure on the image and retain the bright spots formed by touching the screen; 3) Based on the enhancement algorithm, adjust the enhancement and blur to make the highlights on the image clear.

2. The interactive projection noise reduction method according to claim 1, characterized in that: The method further includes: setting a maximum area and a minimum area of ​​a target bright spot, and extracting the target bright spot according to the size of the bright spot area on the image; The maximum area of ​​the target bright spot is Smax, the minimum area of ​​the target bright spot is Smin, and the area of ​​a bright spot on the laser plane image is S; If Smax≥S≥Smin, the bright spot is determined to be the target bright spot.

3. The method for noise reduction of an interactive projection system according to claim 1, characterized in that: The laser wavelength is 808nm, and two layers of filters are installed on the camera, wherein the first layer filters 800-2500nm and the second layer filters 808nm.

4. The method for noise reduction of an interactive projection system according to claim 1, characterized in that: The laser wavelength is 940nm, and two layers of filters are installed on the camera, wherein the first layer filters 800-2500nm and the second layer filters 940nm.

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