KR100844829B1 - Mosaic image creation method and device for the same - Google Patents

Abstract

Disclosed are a mosaic image generating method and a mosaic image generating device. Mosaic image generating method according to the invention comprises the steps of receiving an image to be converted into a mosaic; Dividing the received image into a plurality of cells; Determining a tile corresponding to each of the cells from a plurality of tiles stored in a tile database; Creating a first tile layer by placing each of the determined tiles in a corresponding cell; And stacking a second tile layer having a first angle difference with the first tile layer on the first tile layer, thereby generating a mosaic image close to the original image.

Mosaic images, tiles

Description

Mosaic image creation method and device for the same}

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the drawings cited in the detailed description of the invention, a brief description of each drawing is provided.

1 is a functional block diagram of a mosaic image generating apparatus according to an embodiment of the present invention.

2 illustrates a mosaic image generating method according to an embodiment of the present invention.

3A and 3B illustrate images of a rotatable object used when generating a mosaic image according to an embodiment of the present invention.

4 is a diagram for describing tile matching according to an exemplary embodiment of the present invention.

5 illustrates a method of determining a tile according to an embodiment of the present invention.

6 are images of sampled objects used in generating a mosaic image according to an embodiment of the present invention.

7A and 7B are diagrams for describing a shadow effect according to an embodiment of the present invention.

8A to 8C are diagrams for describing a method of generating a multilayer mosaic image.

9 illustrates a generated mosaic image according to an embodiment of the present invention.

The present invention relates to a mosaic image generating method and a mosaic image generating apparatus, and more particularly, to a method and a mosaic image generating apparatus for generating a multilayer mosaic image using an image of a rotatable object.

In general, non-photorealistic rendering is a technique of rendering objects by various non-realistic rendering methods, which is a concept contrary to conventional photorealistic rendering.

For example, the non-realistic rendering can render an object into an unrealistic artistic image using various art materials (eg, mosaic, color pencil drawing, pen drawing, oil painting, watercolor, charcoal drawing, or cartoon). .

Recently, non-realistic rendered images are reflected in the industry, and are used in game, film, animation, advertisement, medical, architecture, or mechanical fields, and computer graphic tools capable of expressing the images are being developed.

In particular, the photo-mosaic non-realistic rendering technique using a computer graphic tool divides the original image into a plurality of cells, and combines the cells with tiles in the form of a small image having a small color difference to produce a rendered image of a large image.

However, when using a non-realistic rendering technique using the mosaic using a computer graphics tool, the computer graphics tool needs a database storing a plurality of tiles to find a tile having a small color difference from the cells.

Therefore, the capacity of the database may be increased to find tiles having smaller color differences with the cells. As the capacity increases, the time required for finding a suitable tile may increase, resulting in an unrealistic rendered mosaic image.

In addition, when the computer graphics tool generates a large image rendered image with the tiles in the form of small images, unwanted margins may be formed between the tiles constituting the generated image. For example, when the tiles are coin images, the mosaic image may be distorted due to the margins between adjacent coins.

Therefore, there is a need for computer graphics tools and mosaic image generation methods that can generate a mosaic image close to the original image with a small number of tiles, and prevent distortion of the mosaic image due to unwanted margins between tiles. to be.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a mosaic image generating method and a mosaic image generating apparatus generating a mosaic image close to an original image with a small number of tiles.

In addition, the technical problem to be achieved by the present invention is to provide a multi-layer mosaic image generating method and a hatch image generating apparatus that can reduce the distortion of the original image by reducing the margin between the tiles.

The mosaic image generating method for achieving the technical problem comprises the steps of receiving an image to be converted into a mosaic; And dividing the received image into a plurality of cells; Determining a tile corresponding to each of the cells from a plurality of tiles stored in a tile database; Creating a first tile layer by placing each of the determined tiles in a corresponding cell; And stacking a second tile layer having a first angle difference from the first tile layer on the first tile layer.

The stacking of the second tile layer on the first tile layer may include rotating the plurality of cells by the first angle; Determining a tile corresponding to each of the rotated cells from a plurality of tiles stored in the tile database; And arranging each of the determined tiles in a corresponding rotated cell to generate a second tile layer.

The mosaic image generating method may further include stacking a third tile layer having a second angle difference from the second tile layer on the second tile layer.

The determining of the tile may include finding, for each cell, a tile having the smallest color difference from the corresponding cell, wherein the color difference corresponds when each pixel of the tile image corresponds to each pixel of the corresponding cell. It may correspond to the accumulated value of the Gr difference value, the Gb difference value, and the Gg difference value between each pixel.

Each of the plurality of tiles is an image of an object rotatable within a predetermined bounding circle, and the determining of the tile may include rotating each of the plurality of tiles by a predetermined angle and corresponding to each of the rotated tiles. The method may include determining a tile having the smallest color and color difference of the cell.

The mosaic image generating method may further include applying a shadow effect to the generated mosaic image.

The image generating method for achieving the technical problem comprises the steps of receiving an image to be converted into a mosaic; Dividing the received image into a plurality of cells; And determining a tile corresponding to each of the cells from a plurality of tiles stored in a tile database. The determining of a tile corresponding to each of the cells may include: rotating each of the plurality of tiles by a predetermined angle to obtain rotated tiles; And comparing the rotated tiles with the corresponding cells to determine the tiles having the smallest difference from the corresponding cells.

The tile having the smallest difference from the corresponding cell has the highest accumulated value of Gr difference, Gb difference, and Gg difference between the corresponding pixels when each pixel of the tile image corresponds to each pixel of the corresponding cell. It may be a small tile.

Mosaic image generating apparatus for achieving the technical problem is an image receiving module for receiving an image to be converted into a mosaic; A tile database for storing a plurality of tiles; And a mosaic conversion module configured to receive an image from the image receiving module, divide the received image into a plurality of cells, and stack a tile corresponding to each of the cells on each of at least two tile layers to generate a mosaic image. All.

The mosaic conversion module may include: a tile determination module which divides an image to be converted into a mosaic into a plurality of cells and determines a tile corresponding to each of the cells from the plurality of tiles; And an image processor configured to stack a tile determined by the tile determination module on at least two tile layers to generate a mosaic image.

The tile determination module finds a tile having the smallest color difference with the corresponding cell for each cell, and the color difference corresponds to the Gr difference value between the corresponding pixels when each pixel of the tile image corresponds to each pixel of the corresponding cell. , Gb difference value, and Gg difference value may correspond to the accumulated value.

The image processor generates a first tile layer by arranging each tile determined by the tile determination module in a corresponding cell, and a second tile layer having a first angle difference from the first tile layer is disposed on the first tile layer. Can be stacked.

Each of the plurality of tiles is an image of an object rotatable within a predetermined bounding circle, and the tile determination module rotates each of the plurality of tiles by a predetermined angle, and the corresponding cell of each of the rotated tiles Determining a tile having the smallest color and color difference.

The image processor may apply a shadow effect to the generated mosaic image.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a functional block diagram of a mosaic image generating apparatus according to an embodiment of the present invention, Figure 2 shows a mosaic image generating method according to an embodiment of the present invention. 1 and 2, the mosaic image generating apparatus 10 includes an image receiving module 20, a tile database 30, and a mosaic transform module 40.

Here, the mosaic image generating apparatus 10 may mean a general PC, a server, or a computer system, and may be implemented by hardware (H / W) and / or software (S / W).

The image receiving module 20 receives an image to be converted into a mosaic (S10), and the tile database 30 stores a plurality of tiles.

Each of the plurality of tiles may be a small image or an image used when generating a mosaic image, and may be an image of a rotatable object.

For example, FIGS. 3A and 3B are diagrams illustrating images of a rotatable object used when generating a mosaic image according to an embodiment of the present invention. The image of the rotatable object includes a wallet, a guitar, a credit card, a mobile phone (FIG. 3A), Or a hammer (FIG. 3B) or the like.

In addition, as shown in the hammer image of FIG. 3B, the tile image according to the present invention may be an image in a predetermined bounding area so that there is no data loss even after the rotation conversion.

Each tile image stored in the tile database 30 is preferably a basic image (unrotated image) of the rotatable object. However, the tile database 30 may further store various tile images obtained by rotating the tile image at a predetermined sampling angle.

For example, as illustrated in FIG. 6, the tile database 30 may store a first tile (memorial coin form image) and a plurality of rotated images of rotating the tile at a predetermined angle.

However, in this case, since the actual storage capacity of the database 30 is increased, only the basic image (not rotated image) of each tile image is stored in the actual database, and when the tile is matched, the basic tile image is rotated at a predetermined angle to variously. You can get a rotating tile image and get the same effect as the database is increased.

A detailed method of obtaining various tile images by rotating the tile image at a predetermined sampling angle will be described later with reference to FIG. 5.

The mosaic conversion module 40 determines the number of tile layers in which the mosaic-converted image is to be generated (S20), receives the image from the image receiving module 20, and divides the received image into a plurality of cells ( S30).

The number of tile layers may be set by a user, and a preset value may be stored.

Each of the cells represents a shape of a divided image, and may be an image of a square, diamond, rectangle, circle, or heart, and may be variously modified according to a user's desired image.

In addition, the mosaic transformation module 40 determines a tile corresponding to each of the cells (S40), and matches the determined tile to correspond to the corresponding cell (S50).

The mosaic conversion module 40 includes a tile determination module 42 and an image processor 44. The tile determination module 42 divides the image to be converted into a mosaic into a plurality of cells, and determines a tile corresponding to each of the cells from the plurality of tiles (S30).

For example, FIG. 4 is a diagram illustrating tile matching according to an exemplary embodiment of the present invention. Referring to FIGS. 1 and 4, the image processor 44 may include a plurality of rectangular images of an image IM1 to be converted into a mosaic. Split into cells of.

The tile determination module 42 determines, for each cell, a tile having the smallest distance difference (eg, color difference or brightness difference) from the corresponding cell (eg, C1) (S40), and the image processor 44 The tile layer MI1 is generated by matching the determined tile to correspond to the corresponding cell (eg, C2) (S50).

The color difference may correspond to a value obtained by accumulating Gr difference, Gb difference, and Gg difference between each pixel (pixel) of the tile image and the corresponding pixel (pixel) of the cell image when comparing the tile image and the cell image. Can be.

Each of the Gr difference value, the Gb difference value, and the Gg difference value is a difference value between a red component, a blue component, and a green component between each pixel of the tile image and the corresponding pixel of the cell image. Indicates.

In this case, when the size of the tile image and the size of the cell image are different, the size of the tile image is enlarged or reduced to correspond to the size of the cell image, and the size of the tile image is enlarged or reduced to correspond to the size of the cell image. After mapping each pixel to each pixel of the corresponding cell, a color difference between the corresponding pixels may be obtained.

For example, the color difference may be calculated by Equation 1 below.

However, each of Gr (i, j), Gg (i, j), and Gb (i, j) is a pixel of each of the divided cells among cells in which the image IM1 to be converted into mosaic is divided by i * j. Red, green, and blue components, and Tr (i, j), Tg (i, j), and Tb (i, j) represent the red, green, and blue of the (i, j) cells created in the tile layer. Means ingredients.)

The tile determination module 42 may determine the image having the smallest color difference by calculating the color difference of each rotated image while rotating the tile stored in the tile database 30 by a predetermined sampling period.

For example, FIG. 5 illustrates a method of determining a tile according to an embodiment of the present invention, and FIG. 6 is images of a sampled object used in generating a mosaic image according to an embodiment of the present invention. 5 and 6, the tile determination module 42 has a color of the cell C1 corresponding to the first tile (eg, the image of the commemorative coin of FIG. 6) stored in the tile database 30. The difference is calculated (S401).

The tile determination module 42 calculates a color difference for each of the sampling angles while rotating the first tile by a predetermined sampling angle (for example, N degrees (N is a natural number, 30)) (S403).

The tile determination module 42 determines a tile having the smallest color difference among the rotated first tiles based on the color difference (S405).

That is, according to the present invention, the tile determination module 42 rotates a tile image at a predetermined sampling period to determine an image having the smallest color difference based on the color difference of each rotated image, thereby increasing the tile database. The same effect can be obtained.

In addition, when the original image is a gray-scale image, a tile image having a small distance difference from the corresponding cell may be determined by obtaining a difference in brightness or gray level, not a color difference between the tile image and each cell.

The image processor 44 may apply a shadow effect to the generated mosaic image (S60). The shadow effect applying step (S60) is a step for giving a three-dimensional feeling or weight to the generated mosaic image, to process the color of the edge (edge) of the tiles constituting the mosaic image, or to contrast in the margin between adjacent tiles By providing a more realistic mosaic image can be generated.

For example, FIGS. 7A and 7B are diagrams for describing a shadow effect according to an exemplary embodiment of the present invention. FIG. 7A is a diagram before applying a shadow effect to a mosaic image, and FIG. 7B is a diagram after applying a shadow effect to a mosaic image. As a figure, it can be seen that the mosaic image of FIG. 7B has a greater stereoscopic and realistic feeling than the mosaic image of FIG. 7A.

The image processor 44 generates a mosaic image by stacking tiles determined by the tile determination module 42 on at least two tile layers.

For example, the image processor 44 determines whether the number of the current tile layers is smaller than the number of the designated tile layers (S70). When the number of the current tile layers is greater than or equal to the number of the designated tile layers, the mosaic image generation is terminated.

However, if the number of current tile layers is smaller than the number of tile layers specified, the image processor 44 rotates the divided original image (that is, the divided cells) at a predetermined angle (S80), for each of the rotated cells. In step S40, the mosaic image generating method is performed.

In an embodiment of the present invention, the second tile layer may be generated by determining corresponding tiles for the rotated cells.

8A to 8C are diagrams for describing a method of generating a multilayer mosaic image. 1 and 8A to 8C, the image processor 44 generates a first tile layer (FIG. 7A) having the same number of cells as the divided original image, and differs from the first tile layer by a first angle. A second tile layer having a can be stacked on the first tile layer (Fig. 7b).

In addition, the image processor 44 may stack a third tile layer having a second angle difference from the second tile layer on the second tile layer stacked on the first tile layer (FIG. 7C).

Therefore, according to the present invention, the image processing unit 44 overlaps the mosaic tile layer in multiple layers, thereby filling empty spaces that may occur between adjacent tiles, and may generate a mosaic image closer to the original.

9 illustrates a generated mosaic image according to an embodiment of the present invention. Referring to FIG. 9, it can be seen that an image of a girl wearing a uniform has been processed into a mosaic image composed of a plurality of tiles and thus converted into a more realistic and three-dimensional image.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. And functional programs, codes and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

As described above, the mosaic image generating method and the mosaic image generating apparatus according to the present invention can generate a mosaic image using an image of a rotatable object, thereby reducing the capacity of the tile database and reducing the mosaic image generation time.

In addition, the mosaic image generating method and the mosaic image generating apparatus according to the present invention have an effect of generating a mosaic image close to the original image by filling the empty space between adjacent tiles by generating a multilayer mosaic image.

Claims (15)

Receiving an image to be converted into a mosaic; And Dividing the received image into a plurality of cells; Determining a tile corresponding to each of the cells from a plurality of tiles stored in a tile database; Creating a first tile layer by placing each of the determined tiles in a corresponding cell; And Stacking a second tile layer having a first angle difference from the first tile layer on the first tile layer. The method of claim 1, wherein the stacking of the second tile layer on the first tile layer comprises: Rotating the plurality of cells by the first angle; Determining a tile corresponding to each of the rotated cells from a plurality of tiles stored in the tile database; And Placing each of the determined tiles in a corresponding rotated cell to generate a second tile layer. The method of claim 2, wherein the mosaic image generating method comprises: And stacking a third tile layer having a second angle difference from the second tile layer on the second tile layer. The method of claim 1, wherein determining the tile comprises: For each cell, finding the tile with the smallest color difference from that cell; The color difference corresponds to a value obtained by accumulating Gr difference values, Gb difference values, and Gg difference values between corresponding pixels when each pixel of a tile image corresponds to each pixel of a corresponding cell. The method of claim 1, wherein each of the plurality of tiles, Is an image of a rotatable object within a given bounding circle, Determining the tile, Rotating each of the plurality of tiles by a predetermined angle and determining a tile having the smallest color and color difference of the corresponding cell for each rotated tile. The method of claim 1, wherein the mosaic image generating method comprises: The method of claim 1, further comprising applying a shadow effect to the generated mosaic image. Receiving an image to be converted into a mosaic; Dividing the received image into a plurality of cells; And Determining a tile corresponding to each of the cells from a plurality of tiles stored in a tile database, Determining a tile corresponding to each of the cells, Rotating each of the plurality of tiles by a predetermined angle to obtain rotated tiles; And Comparing the rotated tiles with the corresponding cells, and determining a tile having the smallest difference from the corresponding cells. The tile of claim 7, wherein the tile having the smallest difference from the corresponding cell is A method of generating a mosaic image in which each pixel of a tile image corresponds to each pixel of a corresponding cell, wherein the accumulated Gr difference value, Gb difference value, and Gg difference value between each corresponding pixel are the smallest tiles. A recording medium having recorded thereon a program for carrying out the method according to any one of claims 1 to 8. An image receiving module for receiving an image to be converted into a mosaic; A tile database for storing a plurality of tiles; And Mosaic image generation comprising a mosaic conversion module for receiving an image from the image receiving module and partitions the received image into a plurality of cells, and generates a mosaic image by stacking tiles corresponding to each of the cells on at least two tile layers, respectively. Device. The method of claim 10, wherein the mosaic conversion module, A tile determination module for dividing an image to be converted into a mosaic into a plurality of cells and determining a tile corresponding to each of the cells from the plurality of tiles; And And an image processor configured to generate a mosaic image by stacking tiles determined by the tile determination module on at least two tile layers. The method of claim 11, wherein the tile determination module, For each cell, the tile having the smallest color difference from the corresponding cell is found. The color difference corresponds to the difference between Gr, Gb, And a mosaic image generating device corresponding to a value obtained by accumulating Gg difference values. The method of claim 11, wherein the image processing unit, Generating a mosaic image by arranging each tile determined by the tile determination module in a corresponding cell to generate a first tile layer and stacking a second tile layer having a first angle difference with the first tile layer on the first tile layer. Device. The method of claim 11, wherein each of the plurality of tiles, Is an image of a rotatable object within a given bounding circle, And the tile determining module rotates each of the plurality of tiles by a predetermined angle and determines a tile having the smallest color and color difference of the corresponding cell for each rotated tile. The method of claim 11, wherein the image processing unit, Mosaic image generating device that applies a shadow effect to the generated mosaic image.

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