KR101959744B1 - Method and apparatus for correction of projection based on image - Google Patents

Abstract

The present invention relates to a method and an apparatus for correcting projection based on an image. The method for correcting projection based on an image comprises the following steps: receiving a projection image by using an image projection apparatus; determining a reference point on the projection image by using the image projection apparatus; and correcting a position of the projection image on a projection plane based on the reference point by using the image projection apparatus.

Description

[0001] The present invention relates to an image-based projection correction method and apparatus,

The present invention relates to an image-based projection correction method and apparatus. And more particularly, to a projection image position correcting method and apparatus for correcting a position of a projection image by setting a reference point in a projection image output on a projection plane.

With the development of media technology, the application of media technology to museums and exhibition halls is continuously increasing. Accordingly, the market for beam projectors that output media images is expected to continue to grow.

In the past, the aspect of the exhibition that physically watched the work of a specific artist is now changing to be combined with advanced technology. The 'Quarry of Light' is an example of overseas recreation of previously abandoned space based on media art technique called culture and software mixture.

Lex Baux de Province is a representative example of a successful example of a local government combining cutting-edge science and technology as a venue for art and media art exhibitions. . A huge quarry that has been mined for more than 100 years, named Carrieres de Lumieres, has been abandoned after the abandonment of a limestone cave. It was used as an art exhibition hall.

There are about 70 beam projectors installed on the ceiling inside the exhibition hall, which has a large space unique to the quarry, projecting images on the walls and the whole floor.

In the case of the projection mapping operation, the position of the beam projector changes due to a physical external impact in the field, and the projected surface is frequently distorted. In this case, it leads to the maintenance burden of the construction company and the operating agency. In the case of the hall or the conference room using the beam projector in addition to the projection mapping, the same problem is continuously occurring.

There is an inconvenience that the remote controller operation process must be performed in the case of an expensive beam projector that supports the screen correction function.

Therefore, there is a need for a method of correcting the projection image more conveniently and accurately.

It is an object of the present invention to solve all the problems described above.

Another object of the present invention is to effectively correct the movement of the projection image projected on the projection screen due to the movement of the beam projector.

Another object of the present invention is to correct a projection image based on a reference point by setting a reference point on the projection image.

In order to accomplish the above object, a representative structure of the present invention is as follows.

According to one aspect of the present invention, an image-based projection correction method includes the steps of: receiving a projection image by an image projection apparatus; determining a reference point on the projection image by the image projection apparatus; And correcting the position of the projection image on the projection plane with reference to the reference point.

According to another aspect of the present invention, there is provided an image projection apparatus for performing projection correction based on an image, comprising: an image pickup unit configured to receive a projection image; a reference point determination unit configured to determine a reference point on the projection image; And a projection corrector configured to correct the position of the projection image on the projection plane with reference to the reference point.

According to the present invention, the movement of the projection image projected on the projection screen due to the movement of the beam projector can be effectively corrected.

Further, by setting a reference point on the projection image, a projection image projected on a plane or a three-dimensional image based on the reference point can be accurately corrected.

1 is a conceptual diagram illustrating an image projection apparatus according to an embodiment of the present invention.
2 is a conceptual diagram illustrating a projection image correction method according to an embodiment of the present invention.
3 is a conceptual diagram illustrating a method of setting a reference point according to an embodiment of the present invention.
4 is a conceptual diagram illustrating a method of setting a reference point according to an embodiment of the present invention.
5 is a conceptual diagram illustrating a method for determining movement of a projection image based on a plurality of segmentations according to an embodiment of the present invention.
6 is a conceptual diagram illustrating a method for determining movement of a projection image based on a plurality of reference points according to an embodiment of the present invention.
7 is a conceptual diagram illustrating correction of a projection image according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, the specific shapes, structures, and characteristics described herein may be implemented by changing from one embodiment to another without departing from the spirit and scope of the invention. It should also be understood that the location or arrangement of individual components within each embodiment may be varied without departing from the spirit and scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention should be construed as encompassing the scope of the appended claims and all equivalents thereof. In the drawings, like reference numbers designate the same or similar components throughout the several views.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is a conceptual diagram illustrating an image projection apparatus according to an embodiment of the present invention.

FIG. 1 illustrates an image projection apparatus for correcting an image projection of a projector by determining a current state based on a captured image.

1, the image projection apparatus may include a projection unit 100, an image pickup unit 110, a reference point determination unit 120, a projection correction unit 130, and a processor 140.

The projection unit 100 may be implemented to output a projection image using a projector to a projection target. The object to be projected may be various shapes such as a flat surface and a three-dimensional surface.

The image capturing unit 110 may be implemented to perform capturing of a projection image output to a projection object. The projection image sensed by the image sensing unit 110 may be input to the reference point determination unit 120 and / or the projection correction unit 130. For example, the image capturing unit 110 may be implemented at the top of the projector / inside the projector for capturing an image of a surface to be projected by the projector, and may perform real-time shooting while being projected.

The reference point determination unit 120 may be implemented to determine a reference point as a reference for performing image correction. The reference point may be a point that does not change even when a project image is output on the projection plane. In other words, the reference point may include a point or a line segment on the projection image existing at a position that does not change with the positional change of the projection image.

 The projection plane may be flat or three-dimensional. It is possible to determine a change of the projection image to determine a reference point and to extract a point that does not change on the projection image. The reference point may be set to a plurality of points to determine the motion of the projection image.

The projection correction unit 130 may be implemented for correction of the projection based on the projection image. The projection correction unit 130 can determine whether or not the projection image needs to be corrected based on the reference projection image. If correction for the projection image is required, the correction information can be determined to correct the current projection image .

The processor 140 may be implemented to control operations of the projection unit 100, the image pickup unit 110, the reference point determination unit 120, and the projection correction unit 130.

Hereinafter, in the embodiment of the present invention, a method of correcting a projection image is specifically disclosed.

2 is a conceptual diagram illustrating a projection image correction method according to an embodiment of the present invention.

FIG. 2 illustrates a method of performing image correction based on an analysis of a projected image of a captured image of the image capturing unit.

Referring to FIG. 2, a specific point and / or a specific region may be set as a reference point 200 within the web camera photographing region of the image pickup section. For example, the reference point 200 may be a point based on an edge of an object in the image, a specific point of the object, or a brightness (contrast).

When the reference point 200 is determined, data for the reference point 200 may be stored. Position information within the projection image of the set reference point 200 can be stored as data. The reference point 200 may be a point that does not change even when a change in the projection image occurs. In addition, information on a reference image that is a reference for setting the position information of the reference point 200 may also be stored.

If the projector is moved, the reference image may be changed and the information about the reference point 200 may be changed.

The image correction unit may extract information on the change of the reference point 200 and may perform image correction based on the reference point change information.

3 is a conceptual diagram illustrating a method of setting a reference point according to an embodiment of the present invention.

In Fig. 3, a method of setting a reference point for determining whether correction is performed in an image is disclosed.

Referring to FIG. 3, change information of a projection image may be collected to determine a reference point. The projection section can output on the projection surface in accordance with the input image information.

The projection image changes according to the change of the image information. Therefore, the setting of the reference point for determining whether or not correction can be determined as a point at which the image characteristic does not change in consideration of the change of the image. For example, when the projection plane is plane, the edge, the corner point, of the plane constituting the projection plane can be set as the reference point. As another example, when the projection plane is three-dimensional, a certain point of the image and the image on the unchanged image generated by projecting the projection image into the three-dimensional body can be set as the reference point.

In order to determine the reference point, the reference point determination unit of the image projection apparatus may perform an analysis on the image. A region that changes with time in the entire region of the image can be removed first.

For example, the entire image region can be divided into the plurality of lower divided regions 300 through the first division in the whole image region, and the detection of the plurality of lower divided regions 300 can be performed. Detection of the non-moving region among the plurality of sub-regions 300 can be performed through detection of the plurality of sub-regions 300.

As a result of the first division, it can be judged whether or not a plurality of non-moving regions among the plurality of sub-regions (hereinafter, candidate object fixed regions 320) exist. If there are a plurality of candidate object fixed areas 320 among the plurality of lower divided areas 300, it may be determined whether or not there is an object to specify a reference point on the plurality of candidate object fixed areas 320.

On the contrary, when there are one or less non-moving regions (hereinafter, candidate object fixed region 320) among the plurality of lower divided regions 300 as a result of the first division, It is possible to extract a plurality of candidate object fixed areas 320 by performing two-division. In this way, the candidate object fixed area 320 can be found in the image while dividing the relatively large sub-area into a relatively small sub-area.

It is difficult to determine the movement of the projection image when there is no object to specify a reference point on a plurality of candidate object fixed areas 320 (for example, a background area) The final object fixed area 340 can be determined.

When there are two or more final object fixed areas 340, the entire area of the image is divided into the plurality of sub-divided areas 300 through the second division in the entire image area, and the candidate object fixed area 320 You can decide. The second partition may be a partition smaller than the first partition.

A specific point of the object located on the final object fixed area 340 may be set as a reference point. A point at which a specific point such as an edge of an object can be formed can be set as a reference point and can be set to determine whether or not the projection image is moving. If an edge of the object does not exist, a line segment equal to the edge of the object may be set as a reference point and set to determine whether the projected image is moving.

Although it is assumed that a plurality of final object fixed areas 340 are set in FIG. 3, it is possible to determine the movement of the projection image even when one final object fixed area 340 is set.

4 is a conceptual diagram illustrating a method of setting a reference point according to an embodiment of the present invention.

In Fig. 4, a method of setting a reference point for determining whether correction is performed in an image is disclosed. In particular, a method for performing a determination on movement of a projection image even when one final object fixed area is set is disclosed.

Referring to FIG. 4, even if the candidate object fixed area is one, the determination of the movement of the projection image can be performed by setting the candidate object fixed area as the final object fixed area.

If there is an object to specify a reference point in the fixed object region of the candidate object and an edge 400 having a certain angle or more exists in the object, Judgment can be performed.

One edge 400 may serve as a plurality of reference points 420 and the movement of the projection image may be determined based on the plurality of reference points 420.

In this case, in order to perform a more accurate determination of the movement of the projection image, even if the angle of the edge 400 is equal to or greater than the threshold angle, even if the candidate object fixed area is 1, the candidate object fixed area is set as the final object fixed area, Can be performed.

When the edge 400 exists, the edge 400 may serve as a plurality of reference points 420, and correction for the projection image may be possible through the edge 400.

The image-based projection correction method includes the steps of: receiving a projection image by an image projection apparatus; determining a reference point on the projection image by the image projection apparatus; determining a position of the projection image on the projection plane May be corrected.

The reference point may include a point or a line segment on the projection image which is located at a position that does not change even when the position of the projection image changes. The reference point is determined on a plurality of lower divided regions obtained by dividing the entire image region, the reference point is extracted on a candidate object fixed region including an object having an image feature that does not change on a plurality of lower divided regions, If a plurality of sub-divided regions are not extracted, each of the plurality of sub-divided regions may be further divided into a relatively smaller size to search for the candidate object fixed region again.

The reference point is determined on a plurality of lower divided regions obtained by dividing the entire image region, the reference point is extracted on a candidate object fixed region including an object having an image feature that does not change on a plurality of lower divided regions, If a plurality of reference points are not extracted, it is possible to determine whether or not an edge of a threshold angle or more exists in the candidate object fixed area and extract a plurality of reference points from the edge.

5 is a conceptual diagram illustrating a method for determining movement of a projection image based on a plurality of segmentations according to an embodiment of the present invention.

In Fig. 5, a method for determining movement of a projection image through a plurality of division is disclosed.

Referring to FIG. 5, when the position of the reference point for determining the movement of the projection image falls below the critical distance, the movement of the projection image can be determined more accurately. If the reference point is less than the critical distance, if the movement of the projection image occurs, the reference point may disappear, and in such a case, it may be difficult to extract the movement information of the projection image. Therefore, it is possible to determine whether the projection image is moved by setting the reference points less than the critical distance as one set.

When the distance between the primary reference points 510 located in the candidate object fixed area determined through the first division is equal to or greater than the critical distance, the secondary reference point 510 is located at a position less than the other primary distance except for the corresponding primary reference point 510 520 may be set.

The secondary reference point 520 located in the candidate object fixed area determined through the second division is additionally determined and whether or not the distance between the secondary reference point 520 and the primary reference point 510 is less than the threshold distance Can be performed.

If the distance is equal to or greater than the critical distance, the primary reference point 510 and the secondary reference point 520 may be set as reference points for determining whether or not the projection image is moved.

If the distance between the secondary reference point 520 and the primary reference point 510 is greater than or equal to the threshold distance, then the setting for the tertiary reference point 530 is again performed through a third partition that is smaller than the second partition .

If the reference point less than the critical distance is not generated through the continuous division, the movement of the projection image can be determined based on the reference point having the widest distance between the reference points.

6 is a conceptual diagram illustrating a method for determining movement of a projection image based on a plurality of reference points according to an embodiment of the present invention.

FIG. 6 discloses a method for more accurately determining movement of a projection image using a plurality of reference point sets.

Referring to FIG. 6, there may be a plurality of reference points determined through the above-described division, and at least two reference points may be set as one reference point set so that a plurality of reference point sets may be determined.

One set of reference points from a plurality of reference point sets may be determined as the main reference point set 600 and the reference points other than the main reference point set 600 may be determined as the sub reference point set 620. [ The sub reference point set 620 may include one reference point among the reference points included in the main reference point set 600. [

The determination as to whether or not the projection image is moved may be performed based on the main reference point set 600 as a priority. Thereafter, when it is determined that the projection image has been moved based on the main reference point set 600, the determination may be performed based on the sub reference point set 620 again.

In addition, the correction of the projection image may be determined by comparing the first movement of the projection image with the second movement of the projection image with reference to the sub reference point set 620 based on the main reference point set 600.

For example, if the first movement and the second movement are similar within the threshold range, movement information of the projection image is determined based on the average of the first movement and the second movement, and based on the movement information of the projection image, Can be performed.

On the contrary, when the first movement and the second movement are not similar within the critical range, information on the third movement,?, And n movement is determined based on another set of sub-reference points 620, Similar movements can be extracted within the threshold range during nth movement. For example, if the second movement, the fourth movement, and the fifth movement are similar movements within the critical range, movement information of the projection image is determined based on the second movement, the fourth movement, and the fifth movement, The correction of the projection image can be performed based on the movement information of the projection image.

According to the embodiment of the present invention, it is possible to set a plurality of reference points in the projection image, and to correct the projection image based on a reference point remaining after movement of the projection image among the plurality of reference points. For example, when it is assumed that the first reference point set, the second reference point set, and the third reference point set are set on the projection image, there may be a case where the reference point included in the first reference point set disappears due to the movement of the projection image . In this case, because the image can not be corrected to the reference point included in the first reference point set, the image correction can be performed based on the second reference point set and the third reference point set. Therefore, it is possible to set a plurality of reference point sets, the reference points included in each of the plurality of reference point sets are set to be located at a position below the critical distance, and each of the plurality of reference point sets can be located and set up so as to exist at a position exceeding the critical distance .

7 is a conceptual diagram illustrating correction of a projection image according to an embodiment of the present invention.

In Fig. 7, a method of correcting a projection image based on a reference point serving as a marker is disclosed.

Referring to FIG. 7, the position in the image of the reference point 700 may be determined as the position of the reference point 700. The reference point position may be a relative position on the entire area in consideration of the entire area of the projection image output on the projection object. For example, when the projection target is a two-dimensional plane, the reference point position can be set by setting the x-axis and the y-axis for the projection image output on the projection target. When the projection object is a three-dimensional solid object, the reference point position can be set based on the x-axis and the y-axis with respect to the projection image output to the three-dimensional solid image.

If the projection image is changed, the relative position of the reference point 700 may be changed, and the change of the projection image position upon correction of the projection image may be determined based on the relative positional change of the reference point 700 .

The embodiments of the present invention described above can be implemented in the form of program instructions that can be executed through various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer-readable recording medium may be those specifically designed and configured for the present invention or may be those known and used by those skilled in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROM and DVD, magneto-optical media such as floptical disks, medium, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code, such as those generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be modified into one or more software modules for performing the processing according to the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the scope of the present invention.

Accordingly, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all ranges that are equivalent to or equivalent to the claims of the present invention as well as the claims .

Claims (8)

In the image-based projection correction method,
Receiving a projection image from an image projection apparatus;
The image projection apparatus determining a reference point on the projection image; And
Wherein the image projection apparatus corrects the position of the projection image on the projection plane with reference to the reference point,
Wherein the reference point includes a point and a line segment on the projection image at a position that does not change with the change of the position of the projection image,
Wherein the image projection apparatus is configured to determine whether the projection image is moved by setting the reference points less than the critical distance as one set,
Wherein the image projection apparatus sets at least two reference points as a set of reference points to determine a plurality of reference point sets,
Wherein the image projection apparatus determines one set of reference points among the plurality of reference point sets as a set of main reference points, determines reference points other than the set of main reference points as a sub reference point set,
Wherein the sub reference point set is configurable to include one of a plurality of reference points included in the main reference point set,
Wherein the image projection apparatus determines movement of the projection image based on the set of main reference points and the set of sub reference points,
Wherein the main reference point set and the reference points included in each of the sub reference point sets are set to be located at a position less than a critical distance and each of the main reference point set and each of the sub reference point sets is located at a position that is greater than or equal to the critical distance. How to. The method according to claim 1,
Wherein the image projection apparatus re-determines whether the projection image is moved based on the sub reference point set when it is determined that the projection image has been moved based on the set of main reference points,
Wherein the image projection apparatus compares the first movement of the projection image based on the set of main reference points with the second movement of the projection image based on the set of sub reference points to determine whether the projection image is corrected,
Wherein the image projection apparatus determines information about a third movement based on another set of sub-reference points when the first movement and the second movement are not similar within the threshold range, Lt; RTI ID = 0.0 > a < / RTI > critical range. 3. The method of claim 2,
When the distance between the first reference points located in the candidate object fixed area determined through the first division is greater than or equal to the critical distance, the image projection apparatus is configured to calculate a second reference point , ≪ / RTI &
The image projection apparatus additionally determines the secondary reference point located in the candidate object fixed area determined through the second division and determines whether the distance between the secondary reference point and the primary reference point is less than a critical distance, And determining a reference point for determining whether to move the image. delete 1. An image projection apparatus for performing image-based projection correction,
An image sensing unit configured to receive a projection image;
A reference point determination unit configured to determine a reference point on the projection image; And
And a projection corrector configured to correct the position of the projection image on the projection plane with reference to the reference point,
Wherein the reference point includes a point and a line segment on the projection image at a position that does not change with the change of the position of the projection image,
Wherein the image projection apparatus is configured to determine whether the projection image is moved by setting the reference points less than the critical distance as one set,
Wherein the image projection apparatus sets at least two reference points as a set of reference points to determine a plurality of reference point sets,
Wherein the image projection apparatus determines one set of reference points among the plurality of reference point sets as a set of main reference points, determines reference points other than the set of main reference points as a sub reference point set,
Wherein the sub reference point set is configurable to include one of a plurality of reference points included in the main reference point set,
Wherein the image projection apparatus determines movement of the projection image based on the set of main reference points and the set of sub reference points,
Wherein the main reference point set and the reference points included in each of the sub reference point sets are set to be located at a position less than a critical distance and each of the main reference point set and each of the sub reference point sets is located at a position that is greater than or equal to the critical distance. . 6. The method of claim 5,
Wherein the image projection apparatus re-determines whether the projection image is moved based on the sub reference point set when it is determined that the projection image has been moved based on the set of main reference points,
Wherein the image projection apparatus compares the first movement of the projection image based on the set of main reference points with the second movement of the projection image based on the set of sub reference points to determine whether the projection image is corrected,
Wherein the image projection apparatus determines information about a third movement based on another set of sub-reference points when the first movement and the second movement are not similar within the threshold range, And extracts a similar movement within the critical range. The method according to claim 6,
When the distance between the first reference points located in the candidate object fixed area determined through the first division is greater than or equal to the critical distance, the image projection apparatus is configured to calculate a second reference point , ≪ / RTI &
The image projection apparatus additionally determines the secondary reference point located in the candidate object fixed area determined through the second division and determines whether the distance between the secondary reference point and the primary reference point is less than a critical distance, And determines a reference point for determining whether to move the image. delete

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