The creation of an image on a structure

Abstract

A structure is provided depicting an image comprising one or more shapes that can be viewed by a viewer from at least a viewing location. The structure comprises a surface over which there are distributed a pre-determined number of features, wherein each feature is located within non uniform triangular matrix formed from a plurality of Voronoi cells. Each Voronoi cell has a seed, and wherein the average inter-seed distance between seeds outside a boundary of the one or more shapes being background is different to the average inter-seed distance between seeds inside the boundary of the one or more shapes. The pre-determined number of features on the surface is selected so that the image is resolvable to the viewer at a viewing location.

Description

[0001] The creation of an image on a structure

[0002] This document claims priority from AU2024903197 filed 3 October 2024 the contents of which are hereby incorporated by reference in their entirety.

[0003] Technical field

[0004] The present invention relates to structures that form images using individual features provided on the structure as a proxy for pixels of the image.

[0005] Background

[0006] Pointillism is a technique where images are created using small, distinct points or holes applied in patterns. These points, when viewed from a distance, visually blend to form a coherent image. The method relies on the precise placement of these points to convey shape, texture, and depth. This approach is used in various media, including physical substrates. In such cases, smaller shapes can be used in varying multitudes to create the illusion of a detailed image.

[0007] The present invention builds on former techniques used to create images using structures that manipulate how an image is viewed. In embodiments, the present invention may provide a useful alternative to prior techniques used to create images.

[0008] Summary of invention

[0009] In a first aspect there is provided a structure depicting an image comprising one or more shapes that can be viewed by a viewer from at least a viewing location, the structure comprising a surface over which there are distributed a pre-determined number of features, wherein each feature is located within a non uniform triangular matrix formed from a plurality of Voronoi cells, each Voronoi cell having a seed, and wherein the average inter-seed distance between seeds outside a boundary of the one or more shapes is different to the average inter-seed distance between seeds inside the boundary of the one or more shapes, wherein the pre-determined number of features on the surface is selected so that the image is resolvable to the viewer at a viewing location.

[0010] In a second aspect there is provided a method for producing a system or structure depicting an image, the method comprising: converting an image to one or more vector lines within an area of a surface to define one or more shapes, the vector lines defining an image boundary, the surface area outside of the image boundary being background; polygonising the surface including the one or more shapes and the background according to a first setting to populate the surface with first polygons, subjecting the first polygons to a Voronoi iteration to form a plurality of seeds, one for each of the first polygons; removing first polygons from the surface where the Voronoi seed of the polygon is located within the image boundary, OR removing polygons from the surface where the Voronoi seed of the polygon is located outside the image boundary, to create a polygon free area with a perimeter defined by the remaining first polygons; polygonising the polygon free area according to a second setting, using the perimeter defined by the remaining first polygons to populate the surface with second polygons; subjecting first and second polygons to a further Voronoi iteration to form a further plurality of seeds, one for each of the first and second polygons; assigning each of the plurality of seeds as a feature located in the system or on the surface; wherein the first setting and the second setting are selected so that a density of the features of the one or more shapes is different to the density of the features of the background.

[0011] The present structure forms an image using a non-uniform matrix of features. Each of the features is effectively a pixel of the image. It is thought that the viewer’s eye finds lines and or patterns in the features and tracks them to form the image. The contrast between the background pixels (features) and the shape pixels (features) is intended to be a subtle change designed to engage the viewer, rather than to be an immediate and clear image.

[0012] The method of the present invention can provide an image in which the background and shape, both formed from features, are not too distinct from one another. This is achieved by substantially avoiding a line of dots or features at the image boundary. Instead, the pixels (features) of the image are caused to be blended across the surface area.

[0013] The present structure can provide the appearance of an image to an observer. The image is not limited and can be a word, a shape, a picture. Each feature in the image acts as a proxy for a pixel in the image. When viewed close up, the image may not be readily discernible, but as the observer steps back the image can appear.

[0014] The substrate of the surface can be formed from any material including metal, wood, plastic, concrete, paper. The shapes forming the image can contrast with the main area of the substrate by colour, shade, texture, emboss or deboss, superimposition and or removal of the substrate. The resulting patterns can interact with light and or shadow to form larger images, shapes or patterns. In an embodiment, natural features are employed such as water with plants, open air with features, soil with plants or other. For example, plants could be located according to the method to form the image in soil as they grow.

[0015] In an embodiment in which the features are perforations in the substrate the substrate is formed form a material in which perforations can be readily formed. In an embodiment in which the features are coloured or raised, the substrate can be formed from a material which has properties that permit the application of colour, or for an interior part of the perforations to remain attached to the substrate by one or more tabs once the perforation is cut. In a preferred embodiment, the structure is formed from a metal. The metal substrate can be a panel. The panel can be used alongside other panels to form an overall larger image. The panels can be joinable to one another by any connecting means. In an embodiment, the panel is at least about 1 or 2 m in its longest dimension. The panel can be smaller e.g. 0.5m or much bigger e.g. up to 5, 10m or more depending on its use circumstances. The panel can be a few millimetres thick however the thickness of the panel is not limited and instead is dictated by the intended commercial use.

[0016] The substrate can define a reference plane L. The reference plane defines the level surface of the substrate. The reference plane L can have a top end (e.g. where the top of the image will be located) and a bottom end (e.g. where the bottom of the image will be located). If the image does not have a top / bottom for example in the case of the pattern, the top end is at one end and the bottom end is at the end opposite to the top end.

[0017] The substrate is preferably flat or planar. The substrate can be undulating or curved. If the substrate is not planar, this may need to be taken into account when the image is formed on the substrate, since the light might change as it strikes the features in different planes. The substrate can be more amorphous such as a natural background on which the features are overlaid.

[0018] The image is formed on an area of the substrate surface sometimes referred to as the surface area. The surface area can be a defined area of a larger overall surface.

[0019] The features on the substrate, acting as a proxy for pixels, can take the form of perforations or holes in the material. These perforations can be arranged to modulate the passage of light, creating an image through variations in light intensity and or shadow. The reverse image of this could also apply where the features are solid areas with free space being the substrate. Alternatively, or in addition, the pixel-like features on the substrate can consist of areas of contrasting (darker or lighter) color, altered texture, or raised elements such as dimples or tabs. These raised or textured features can reflect, absorb or scatter light differently compared to the surrounding background, thus creating the image. The features acting as a proxy for pixels can be natural features such as plants or rocks.

[0020] Various types of features can be selected from perforations and embossed forms. These can be selected from the features as follows: • Embossed forms which comprise a shaped dimple being pushed upward or downward into the substrate.

[0021] • Whole shapes where the interior of a perforation is removed completely.

[0022] • Partial shapes which retain one or more tabs supporting the middle of each shaped perforation.

[0023] • Solid shapes with a free air background.

[0024] The features can be of any shape. The features can be slots, stadium or sausage shapes, circular, or pebble shapes. In embodiments, the features can be a pebble shape. In some embodiments, changing the shape, size and / or orientation of the feature can change the amount of light that passes through.

[0025] Once a desired image is selected for use, the image is applied to the substrate area using the method. The image is converted into one or more vector lines within the area of the provided surface. This involves transforming a raster image into vector format, where the image is represented by geometric paths such as lines and curves that define the relevant shapes. The vector lines act as boundaries for specific shapes within the image, separating them from the background, which is the area of the surface outside these shapes.

[0026] The surface, including both the one or more shapes and the surrounding background, is divided into smaller polygonal elements. This process is used to create a mesh or grid that covers the surface enabling manipulation of the geometry for applications like computer graphics, 3D modeling or surface analysis. The polygonal elements can be any polygon that is suitable for manipulation including triangles and or quadrilaterals. The first polygons are created based on a first setting. The first setting can be “select triangles with a side length of at least or at most Xmm”. In an embodiment, the average side length of the polygons is set to be in the range of from about 14 to about 22mm such as at most about 14, 15, 16, 17, 18, 19, 20, 21 , or 22mm. The first setting determines how the polygons are generated by the computer software. The first polygons provide a structured representation of the surface. A Voronoi diagram algorithm is applied to the existing first polygons in the polygonal structure. In this process, a seed (or point) is placed inside each of the first polygons and the surface is subdivided based on the proximity of each point to its neighbours. The Voronoi iteration ensures that every point within the surface is associated with the nearest seed, creating Voronoi cells or regions around each seed that cover the entire surface without overlap. This technique is commonly used for surface tessellation, spatial partitioning, and optimisation in areas like computer graphics, procedural generation and geographic modeling. The Voronoi iteration can be undertaken a plurality of times to ensure complete randomisation of the seeds. In an embodiment, the Voronoi iteration is undertaken at least 15, 20 or 25 times.

[0027] Some of the seeds will be located within the boundary of the one or more shapes forming the image (the image boundary). Alternatively, some of the seeds will be located within the area of the background. The next step in the process is to subtract the one or more shapes from the background, or vice versa. To do this, any first polygons which have a seed located on or within the vector boundary lines of the one or more shapes can be removed. The result will be a void space within the background of first polygons.

[0028] Alternatively, if the background is being removed, then any first polygons with seeds on or outside of the vector lines of the one or more shapes can be removed. The result is one or more shapes formed from first polygons on a polygon free background.

[0029] The importance of this step of removing polygons is to create a polygon free area. The polygons are not told to reorder after the removal step, so the perimeter of the polygon free area is made up of the exposed edges of the remaining first polygons. Each first polygon maintains its original shape, and the perimeter that previously bordered the removed polygons now form the perimeter. This results in a jagged, irregular perimeter consisting of all the small, straight edges of the first polygons that were adjacent to the deleted ones. The overall shape of the perimeter depends on the size, arrangement and shape of the remaining first polygons, creating a fragmented, multi-edged perimeter. The fragmented polygonal perimeter is used as the perimeter of the new area in which second polygons are formed. These second polygons can be created in the same way as the first polygons, except a new setting (second setting) is applied during the polygonisation.

[0030] The second polygons are created based on a second setting. The second setting determines how the polygons are generated by the computer software. The second polygons provide a structured representation of the free area of the surface. By applying a second setting that differs from the first setting, the process can ensure that a different “pattern” of shapes forms in the new area. It means that the first polygons are different to the second polygons once formed. The second setting can be “select triangles (or other shape) with a side length of at least or at most Ymm”. Typically, Ymm differs from Xmm. In some embodiments Y = X but instead the shape differs.

[0031] In an embodiment, the average side length of the polygons is set to be in the range of from about 14 to about 22mm such as at most about 14, 15, 16, 17, 18, 19, 20, 21 , or 22mm. While this range overlaps with the first setting range, the second setting can be selected to differ from the first setting.

[0032] In one or all embodiments, the first and second settings allow the formation of features that are about at least about 70, 80 or 90% different to one another. For example, if the first setting is an average side length of a polygon of about 19mm, the second setting can be an average side length of about 16mm (or vice versa).

[0033] Once the second polygons have formed, the entire surface will be populated with polygons. These first and or second polygons are each assigned a Voronoi seed by a Voronoi iteration (which can be performed multiple times like before). In an embodiment, all the polygons are subject to the Voronoi iteration. In an embodiment, only the second polygons are subject to the second Voronoi iteration. The Voronoi seeds following this step become the proxy location for the feature (or pixel) on the surface. The present process can help to reduce any tendency for the features forming the edges of the one or more shapes to all form along the outline. If the features all form along the outline, the image is readily discernible by the human eye. However, by introducing some randomness into the process the image is slightly more difficult to see which makes it more compelling to the viewer.

[0034] It is possible to add some finishing touches to the final image before manufacture. For example, if there are some inadvertent features that line up along the boundary, these can be manually moved to avoid being too close to a line and to provide the perception of randomness.

[0035] The features may be oriented in the same direction relative to adjacent features, or may be orientated in different directions. In embodiments, each feature may be rotated about the seed to change the orientation of the feature relative to adjacent features. In embodiments, each feature may be randomly rotated about the seed. Changing the orientation of each feature relative to adjacent features affects the amount of ‘land’ between adjacent features and therefore the amount of light which passes through the area, making the image slightly more difficult to discern from the background.

[0036] In an embodiment, the density of the one or more shapes is higher than the density of the background. In an alternative embodiment, the density of the one or more shapes is lower than the density of the background.

[0037] The density of the one or more shapes can be adjusted by changing the inter-seed distance between seeds inside the boundary of the one or more shapes and / or by changing the size, shape and orientation of the features located at the seeds. Similarly, the density of the background can be adjusted by changing the inter-seed distance between seeds outside the boundary of the one or more shapes and / or by changing the size, shape and orientation of the features located at the seeds.

[0038] The structure can have a fixed number of features per metre squared. The fixed number of features can dictate the average length of the sides of the polygons in the polygonising step. As the number of features (polygons) increases in a fixed area, the polygons must become smaller to accommodate all the features. This means the average side length of each polygon would decrease as the density increases. In an embodiment, there are at most about 2500, 3000, 3500, 4000, 4500 or 5000 features per m2.

[0039] In an embodiment where the structure may comprise two or more shapes, the density of the features in each shape may be about the same as the other shapes or may be different. In embodiments, the density of the features in each shape of the two or more shapes is about the same.

[0040] Each feature can be at least about 2, 5, 10, 15 or 20 mm in its largest dimension. The features can be larger or smaller than these sizes depending on the size of the structure. The size of the features may be relative to the size of the resultant images required. In some commercial situations, such as for domestic use, a small image may be required which might benefit from small features of less than about 1cm. In some commercial situations, a large image might be required, such as an image on the side of a building or in a roof space, in which case very large features greater than 5cm in their longest dimension might be beneficial.

[0041] The observer can be located at a viewing location to see the image. In an embodiment, the image can be created according to the method described herein so that about 20% of people can see the image when the located at about 6 metres from the structure. In an embodiment, the image can be created so that about 70% of people can see the image when the located at about 8 metres from the structure. In an embodiment, the image can be created so that about 80% of people can see the image when the located at about 10 metres from the structure.

[0042] Once formed, the structure can be viewed in ambient light, or it can be lit using positioned light sources. The structure can be illuminated with light from different light sources incident on the structures at different angles. The different light sources may emit different colours of light, such that the colours appear to mix together when viewed by an observer. The visual effect produced by a structure may be enhanced by applying coatings to the features. For example, a flat or matte white coating may be applied to surfaces of the features and a dark coating may be applied to substrate. Alternatively, the features may be covered with an iridescent or fluorescent coating. Other coatings which enhance, augment or alter reflectivity may also be used to cover the features. The substrate and or the features may themselves be constructed from materials which enhance, augment or alter reflectivity. In an embodiment the substate may be a landscape which may be viewed from a higher location such as a garden or lake with features constructed as islands or areas of vegetation. The substrate may also be a sky whereby the features are suspended either by cables or other means in order to allow the viewer to view the features as a group of shapes contrasting with the sky.

[0043] Brief Description of the Figures

[0044] Embodiments of the invention will now be described with reference to the accompanying drawings which are not drawn to scale and which are exemplary only and in which:

[0045] Figure 1 A is an example of a simple image.

[0046] Figure 1 B is a structure depicting the image of Figure 1 A according to an embodiment of the invention.

[0047] Figure 2A is an example of a simple image.

[0048] Figure 2B is a structure depicting the image of Figure 2A according to an embodiment of the invention.

[0049] Figure 3A is an example of a simple image.

[0050] Figure 3B is a structure depicting the image of Figure 3A according to an embodiment of the invention.

[0051] Figure 4 shows the conversion of an image to one or more vector lines.

[0052] Figure 5 is a close-up showing the fragmented polygonal perimeter once first polygons are removed.

[0053] Figure 6 shows the formation of second polygons in the polygon free area.

[0054] Figure 7 shows the proposed locations of the features based on the template of Figure 6 following a Voronoi iteration.

[0055] Figure 8 shows a perforated structure having exemplary features.

[0056] Figure 9 shows a schematic of a method for producing a structure depicting an image according to an embodiment of the invention.

[0057] Detailed Description of Embodiments of the Invention

[0058] Figure 1A shows an example of a simple image 10. Figure 1 B shows a structure 100 depicting the image of Figure 1A. The image 10 is converted to a plurality of vector lines to define shapes 12 on a background 18, the surface area outside of the image boundary forming the background 18.

[0059] The structure 100 comprises one or more shapes 12 that can be viewed by an observer (not shown) when the observer is at a viewing location in front of the structure 100. The structure 100 has a pre-determined number of features 16 distributed across the surface 14. The viewer’s eye finds lines and or patterns in the features 16 and tracks them to form the image 12. The contrast between the features in the background 18 and the features in the shapes 12 are intended to be a subtle change designed to engage the viewer, rather than to be an immediate and clear image.

[0060] In Figure 1 B, the density of the features 16 of the one or more shapes 12 is about 2700 to about 2800 features per m2, the features having an average diameter of about 8 mm. The density of the features 16 of the background 18 is about 3200 to about 3300 pixels per m2, (the features having an average diameter of about 8mm). In use, it is envisaged that the image can be seen by a viewer located between about 10 to about 20 metres from the structure. Figure 2A shows an example of a further simple image and Figure 2B shows a structure depicting the image of Figure 2A. Similarly, Figure 3A shows an example of a further simple image and Figure 3B shows a structure depicting the image of Figure 3A.

[0061] Each image, e.g. the soaring eagle in Figure 1A, is formed by a plurality of features 16 on the surface 14 of the structure 100 which when viewed together give the overall effect of the image. The features 16 are perforations or holes cut into the substrate of the surface 14, arranged to modulate the passage of light.

[0062] Each feature 16 is located within a Voronoi cell having a seed, wherein the average inter-seed distance between seeds outside a boundary 20 of the one or more shapes 12 (i.e. the background 18) is greater than the average inter-seed distance between seeds inside the boundary 20 of the one or more shapes 12. In Figures 1 B, 2B, and 3B, the density of the features of the one or more shapes 12 is higher than the density of the features of the background. As shown in Figures 1 B, 2B, and 3B, features 16 are pebble-like in shape. Each feature 16 is randomly rotated about the seed to change the orientation of the feature relative to adjacent features.

[0063] In Figure 4, an image which has been is converted to vector lines within an area of the surface 114 is illustrated. The vector lines define a shape 112 and an image boundary 120, the surface area outside of the image boundary 120 being background 118.

[0064] In Figure 5, the surface 114 including the shape 112 and background 118 is polygonised according a first setting to populate the surface with first polygons 122. The first polygons 122 are subjected to a Voronoi iteration to form a plurality of seeds, one for each polygon. Where the Voronoi seeds of the polygon are located within the image boundary 120, the first polygons 122 have been removed, thereby creating a polygon free area 124 within a perimeter defined by the remaining first polygons 122. In Figure 6, the polygon free area 124 is polygonised with second polygons 126 using the perimeter defined by the remaining first polygons 122. The first polygons 122 and second polygons 126 are subjected to a Voronoi iteration to form a plurality of seeds, one for each of the first and second polygons. Each of the plurality of seeds is assigned as a feature located on the surface. The first setting and the second setting are selected so that a density of the features of the one or more shapes is different to the density of the features of the background

[0065] Figure 7 illustrates a surface comprising generally circular perforations located at each of the seeds formed during the Voronoi iteration. The density of the features of the one or more shapes 130 is higher than the density of the features of the background 132. This can be achieved by selecting the first setting and the second setting (such as the average side length of the polygons) so that a density of the features of the one or more shapes is different to the density of the features of the background. Alternatively, a density of features of the background can be selected to be higher than the density of the features of the one or more shapes.

[0066] In Figure 8, a perforated structure 230 having a plurality of features 232 is shown. Features 232 are pebble-shaped perforations and are randomly-rotated about the seed of the Voronoi cell.

[0067] In Figure 9, a method for producing a structure depicting an image according to an embodiment of the invention is illustrated. In Step A, an image is converted to one or more vector lines within an area of a surface to define one or more shapes, the vector lines defining an image boundary, the surface area outside of the image boundary being background.

[0068] In Step B, the surface including the one or more shapes and the background is polygonised according to a first setting to populate the surface with first polygons. This process is used to create a mesh or grid that covers the surface enabling manipulation of the geometry for applications like computer graphics, 3D modeling or surface analysis. The first setting determines how the polygons are generated by the computer software. The first polygons provide a structured representation of the surface. In Step C, the first polygons are subject to a Voronoi iteration to form a plurality of seeds, one for each of the first polygons. A Voronoi diagram algorithm is applied to the existing first polygons in the polygonal structure. In this process, a seed (or point) is placed inside each of the first polygons and the surface is subdivided based on the proximity of each point to its neighbours. The Voronoi iteration ensures that every point within the surface is associated with the nearest seed, creating Voronoi cells or regions around each seed that cover the entire surface without overlap.

[0069] In Step D, the first polygons are removed from the surface where the Voronoi seed of the polygon is located within the image boundary to create a polygon free area with a perimeter defined by the remaining first polygons. Alternatively, the first polygons are removed from the surface where the Voronoi seed of the polygon is located outside the image boundary to create a polygon free area with a perimeter defined by the remaining first polygons.

[0070] The importance of this step of removing polygons is to create a polygon free area. The polygons are not told to reorder after the removal step, so the perimeter of the polygon free area is made up of the exposed edges of the remaining first polygons. Each first polygon maintains its original shape, and the perimeter that previously bordered the removed polygons now form the perimeter.

[0071] In Step E, the polygon free area is polygonised according to a second setting, using the perimeter defined by the remaining first polygons to populate the surface with second polygons. The second setting determines how the polygons are generated by the computer software. The second polygons provide a structured representation of the free area of the surface. By applying a second setting that differs from the first setting, the process can ensure that a different “pattern” of shapes forms in the new area. It means that the first polygons are different to the second polygons once formed.

[0072] In Step F, the first and second polygons are subjected to a further Voronoi iteration to form a further plurality of seeds, one for each of the first and second polygons. In Step G, each of the plurality of seeds is assigned as a feature located on the surface. The first setting and the second setting are selected so that a density of the features of the one or more shapes is different to the density of the features of the background.

[0073] The present process reduces any tendency for the features forming the edges of the one or more shapes to all form along the outline. If the features all form along the outline, the image is readily discernible by the human eye. However, by introducing some randomness into the process the image is slightly more difficult to see which makes it more compelling to the viewer.

[0074] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

[0075] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[0076] Any promises made in the present description should be understood to relate to some embodiments of the invention and are not intended to be promises made about the invention as a whole. Where there are promises that are deemed to apply to all embodiments of the invention, the applicant / patentee reserves the right to later delete them from the description and does not rely on these promises for the acceptance or subsequent grant of a patent in any country.

Claims

CLAIMS1 . A method for producing a structure depicting an image, the method comprising: converting an image to one or more vector lines within an area of a surface to define one or more shapes, the vector lines defining an image boundary, the surface area outside of the image boundary being background; polygonising the surface including the one or more shapes and the background according to a first setting to populate the surface with first polygons, subjecting the first polygons to a Voronoi iteration to form a plurality of seeds, one for each of the first polygons; removing first polygons from the surface where the Voronoi seed of the polygon is located within the image boundary, OR removing polygons from the surface where the Voronoi seed of the polygon is located outside the image boundary, to create a polygon free area with a perimeter defined by the remaining first polygons; polygonising the polygon free area according to a second setting, using the perimeter defined by the remaining first polygons to populate the surface with second polygons; subjecting first and second polygons to a further Voronoi iteration to form a further plurality of seeds, one for each of the first and second polygons; assigning each of the plurality of seeds as a feature located on the surface; wherein the first setting and the second setting are selected so that a density of the features of the one or more shapes is different to the density of the features of the background.

2. The method of claim 1 , wherein the Voronoi iteration and or the further Voronoi iteration is undertaken a plurality of times.

3. The method of claim 1 or 2, wherein first polygons are removed from the surface where the Voronoi seed of the polygon is located within a boundary of the one or more shapes.

4. The method of any one of the preceding claims, wherein there are a predetermined number of features within the surface area.

5. The method of claim 4, wherein the predetermined number of features is 3000 features per m2.

6. The method of any one of the preceding claims, wherein the polygons are triangular so the step of polygonising is a step of triangularisation.

7. The method of any one of the preceding claims, wherein the first setting comprises selecting the length of a side of the polygon.

8. The method of claim 7, wherein the first setting is average side length of the polygon is 19mm.

9. The method of any one of the preceding claims, wherein the second setting is average side length of the polygon is 15.9mm.

10. The method of any one of the preceding claims, wherein the density of the features in the one or more shapes is greater than the density of the features of the background.

11. The method of any one of the preceding claims, wherein the features are perforations.

12. The method of any one of the preceding claims, wherein the position of at least some of the features are manually adjusted if they align along the image boundary.

13. The method of any one of the preceding claims, wherein the method comprises the step of uncoupling the image boundary from the perimeter defined by the remaining first polygons.

14. A structure depicting an image produced using a method according to any one of the preceding claims.

15. A structure depicting an image comprising one or more shapes that can be viewed by a viewer from at least a viewing location, the structure comprising a surface over which there are distributed a pre-determined number of features, wherein each feature is located within non uniform triangular matrix formed from a plurality of Voronoi cells, each Voronoi cell having a seed, and wherein the average inter-seed distance between seeds outside a boundary of the one or more shapes being background is different to the average inter-seed distance between seeds inside the boundary of the one or more shapes, wherein the pre-determined number of features on the surface is selected so that the image is resolvable to the viewer at a viewing location.

16. The structure of claim 15, wherein the average inter-seed distance between seeds outside the boundary of the one or more shapes is greater than the average inter-seed distance between seeds inside the boundary of the one or more shapes.

17. The structure of claim 15 or claim 16, wherein the features are an irregular shape.

18. The structure of claim 17 wherein each of the features are randomly rotated about a centre point of the feature.

19. The structure of any one of claims 15 to 18, wherein the features are perforations.

20. The structure of any one of claims 15 to 19, wherein the predetermined number of features is 3000 features per m2.

Images