KnittingMachineAriadne Preparing patterns for AYAB using GIMP

Patterns for use with the AYAB software need to be provided as png files in 2 colours (this is in standard mode - when we work out how to do 4 colour knitting we'll add instructions for that). As Ariadne has 200 needles (if they're all in place), the file must be a maximum of 200 pixels wide, but can be any height(?).

The following steps describe how to use GIMP to convert an SVG file into black and white, but most of it should apply to other file types too:

• Open GIMP then choose File > Open from the toolbar. Find the image you want and open it:

• Set the width in pixels to the number of needles you want to use on the knitting machine (maximum 200):

• Click Open. You should see your image:

• Knitting stitches aren't the same shape as regular pixels - they're rectangles which are shorter than they are wide. You need to compensate for this by stretching the image vertically. From the menu bar choose Image > Scale Image:

• Click the chain symbol to the right of the width and height boxes so you can change them independently. Increase the height in pixels as required. Apparently the exact proportion depends on the tension and type of yarn used, but generally you need to multiply the height by around 1.3 - 1.5 (making a test square advised if exact proportion is important)).

• Click Scale to apply the new values:

• You should now see an elongated version of your image:

• The checkerboard effect in this image is because it doesn't have a background. Select Image -> Flatten Image. You should see the checkerboard effect replaced by white:

• Although the image should now look ok, it probably has anti-aliasing, where the program tries to make the image look better by including shades of grey where a pixel is on a border between black and white. From the menu bar, select Image > Mode > Indexed, check "Use black and white (1-bit) palette and click Convert. The resulting image will probably look quite blocky - that's because 200 pixels doesn't give you very high resolution:

• You can change individual pixels manually. Use the colour picker tool to select the colour you want to use:

• You can use various tools including the pencil tool, to apply the colour to individual pixels / areas:

• To save your file, choose File > Export As from the menu bar. Type in the file name and then click on Select File Type (by Extension) and choose PNG Image, then click Export:

• Uncheck most of the export options as below, and then click Export:

You should now have a file that can be used with the AYAB software.