Cross-stitch is the Western world's most popular form of hobby embroidery, according to Jean Breidenbach, the publisher of a cross-stitch blog. It is also a very old craft, with early examples in the United States dating back to the mid-1600s. However, it wasn't until relatively recently, with the advent of thousands of available shades of embroidery floss, that cross-stitch has been used to "paint" coloured thread images on canvas. Complete sets and stamped patterns are available for purchase, but cross-stitching can be even more satisfying when you use your own images.
Open the image in your photo-editing software. There are several factors to consider in selecting an image. Make sure the image measures at least 640 by 480 pixels. Grzegorz Zochowski with My Cross Stitch recommends selecting images that do not rely on detail for their effect, that have strong contrasts and that are sufficiently large enough on the canvas to preserve important elements.
Adjust the picture however you'd like, including adjusting colour settings, cropping the image, erasing or adding elements. If the image is one that has small details, you can try making it the only focal point of the cross stitch. More squares will give you greater detail.
Apply a pixelated mosaic filter to the image and set the cell size to 5. The method used to apply this filter will vary depending on the photo-editing software you're using, but it is typically found in the "Filters" menu.
Adjust the brightness of the image to bring the details into sharper focus. The tool that does this can sometimes be found in the "Image" menu under adjustments. Colour adjustments may help to even out background colours and thus reduce the colours needed.
Apply a posterize filter to the image. Again, your program will dictate how this is accomplished, but look for the posterize option within the "Image" menu, "Mode" submenu. The posterize level that you set will determine the number of floss colours you'll need to get a pattern for the image that is returned. Generally speaking, Zochowski recommends up to 20 colours for black and white images, 20 to 50 colours for landscapes, 60 to 150 for large images, 5 to 40 colours for a single flower, 10 to 40 colours for animals and 30 to 150 colours for multicoloured images such as a bouquet of flowers.
Create the cross-stitch grid by opening up a new transparent image that measures 5 pixels by 5 pixels or whatever size you set the mosaic cell size to be. With a 1-pixel size brush and black foreground colour, draw a line across the top and along the left side. Set the image as a pattern.
Return to the cross-stitch image and fill the image with the pattern you just made. Be sure to set the pattern at 50 per cent opacity and set the blending mode to darken.
Match the colours in your new chart to the colours on the floss chart. XStitchTreasures offers a simple chart that allows you to match RGB values from your editing software to actual DMC colours. Other floss companies often post their latest palettes online, making this process a bit easier.
If you feel uncomfortable with your photo-editing software, you can opt to download one of several free or paid cross-stitch pattern generators designed just for this purpose.
Be sure to save your cross-stitch pattern separately from the original image if you want to preserve the original for other purposes.