Examine the original image

What to look for and why

You can save a lot of time and effort later in the process of making a tiled image by picking an original image that is free from colour graduations or strong shadows and starts off with an even texture. When you make a tile then repeat it horizontally and vertically to fill a large space any small feature that repeats will stand out because the human eye and brain combination is a superb pattern-recognition engine.

Here is a typical starting image, a photograph of a metal grating. The aim is to produce a tile that can fill any size image or be used as the background for a web page.

Look carefully at the original

Imperfections - obvious problem areas

Here are a couple of problem areas from this image. If these were selected for tiling then if would be necessary to remove the debris. That can be quite a lot of work, especially when the debris is on parts of the image we really want, or it's close to lines or edges of major objects. Where possible it's always better to select a portion of the image that doesn't need a lot of 'cleaning up'.

Tiles are usually square, that makes sense because they work both horizontally and vertically. However, squares are not the only shapes that can be tiled, but they are the easiest.

Select a square portion of the original image

Initial selection and imperfections

Looking at this image we can see that there are raised squares of metal, ideally we want to take a selection that runs exactly half way between these, to start with it may be easier to take a slightly larger selection, then magnify it and crop it neatly.

Here's the initial selection . . . in most image manipulation software there is a marquee tool, holding down the shift key while dragging the mouse with the button held down usually constrains the selection to a square.

In this example some minor imperfections in the image have been circled. If these are not removed they will be very conspicuous in the finished images made from the tile.

Offset the image and clean up

after offsetting

Many image manipulation programs have built-in filters that perform tasks, one such filter is 'offset', which moves the image horizontally and vertically by a fixed amount. Check the size of the image, then offset it by half in each direction. So, if the image is 400 x 400 pixels, offset it by 200 horizontally and 200 vertically.

The new image tile should look something like this.

You should be able to see a horizontal line and a vertical line where the parts of the image have been wrapped around. The next step is to smooth out those lines by cloning small parts of the image and placing them over these joins.

If you are using Photoshop then you can use the 'clone tool' or the 'healing brush' there are tools that achieve the same result in other image manipulation software. An alternative is to select small parts of the image, copy them and paste them over the joins, this will work just as well. At the same time the minor imperfections can be removed using the same technique.

Make the image into a tile

The finished tile

The image is now a tile, it can be saved as an image, or, if your image manipulation software has a facility for making it into a 'pattern' then you can use that.

Try out the tile and check for obvious repeats, these are often caused by debris in the original that has not been cleaned up.

The finished result

5000 x 5000 pixel image created from tile

This final image shows the result of tiling, the original image was 5000 x 5000 pixels and has been scaled to 200 x 200 pixels to show here. There is one of the squares that is a little darker than the others and it shows - it's been left as an example.