Lock and hide “red-layer” and work on “black-layer”. Now we need to use the Select by Color tool (Select -> By Color) to select as much of the red as we can. To do this, I’ve zoomed in quite closely to ensure I can pick the right color and adjust the tolerance up until we can select all of the red we can see. For this image, I’ve use a tolerance of 252 (the maximum).
+Lock and hide “red-layer” and work on “black-layer”. Now we need to use the Select by Color tool (Select -> By Color) to select as much of the red as we can. To do this, I’ve zoomed in quite closely to ensure I can pick the right color and adjust the tolerance up until we can select all of the red we can see. For this image, I’ve used a tolerance of 252 (the maximum).
Now lock and hide "black-layer" and work on “red-layer” and do the opposite: use the above procedure to remove the black lines.
+Now lock and hide "black-layer" and work on “red-layer” and do the opposite: use the above procedure to remove the black lines. Alternatively, if this is difficult, use the select color function on the red lines again and copy and paste these to a new layer, which you can name “red-copy-layer”, then delete “red-layer”.
Tip: it’s a really good idea to retain some “anchor points” at the corners of your image, the same location in each layer, so that when you vectorize, each vector will be of the same outside dimensions. The four corners of a map would be good for this. After tracing, we can remove these anchors from the red layer.
