Capture instructions

1. A correctly drawn set of level curves

   Be as creative as you like! Just make sure not to make any of the following mistakes

   
2. Curves should not overlap

   The curves should have sufficient margin between them, overlapping or close lines are harder to interpret

   
3. Draw with a dark pen

   To recognise your level curves, we prefer a dark and thick marker. Using a lighter pen will likely not work

   
4. Close your curves

   Dont draw any open ended line. Open ended lines will be ignored or misinterpreted.

   
5. Draw in the box

   To make the next step easier, do not draw outside of the square shown on the page

   
6. Do not draw loose ends

   Try to keep your curves neat, as having dangling lines can lead to unintended behaviour.

   

Scan instructions

1. A correct scan

   Try to capture an image where your level curves are the focus of the image.

   
2. Orientation of the scan

   The orientation of your level curves in the camera field highly influences scanning. This example is not parallel, but will probably still work. For best the best result try to scan the paper as close to parallel as possible. This is easiest if you put your paper on a table instead of holding it.

   
3. Four corners visible

   To scan the level curves, we need to have the four corners of the page visible

   
4. Drawing should not be too far

   Scanning works best from a distance of 0.5 meters from the piece of paper.

   
5. Shadows on page

   Level curves are hard to distinguish from the background in a low light setting. Try to use natural daylight or a proper ceiling light for the best results. Be wary of sharp or dark shadows on the drawing, as they might be interpreted as part of your drawing.