 | Step 1. Assume the image is a 1-bit monochrome image. Check
the resolution to make sure parcel boundary lines are
connected. If not, you can use Image/Resize to downsample
by 2 or more. You can also use Image/Despeckle a few times to
remove noise. |
| Step 2. Image/Conversion/Convert to Grayscale. Note: If
you don't want to change the image to grayscale, you can
skip Step 2 and at Step 3, define the color as the
background color, and fill only lines you do not wish to vectorize. After the data is
vectorized, you can save the
vector lines and load the original image as the backdrop
when doing editing. |
| Step 3. Select Image/Image Pixel Tool On, then change to Fill Area
mode. Define the color as 100, or something different
from the background (255) or 0 (lines). Move the cursor
to a parcel line and click the left mouse button to fill.
You'll see all connected parcel lines will turn to the
new color. Repeat this step to fill all parcels. |
| Step 4. Select Image/Set Image Threshold to adjust the threshold to
include only the parcel lines (color around 100) to red
and confirm this. |
| Step 5. Select Vector/Auto Vectorize to make sure the "Use
Defined Image Thresholds" box is checked. Then start
the process to vectorize only parcel boundaries. |
| Step 6. Edit the lines to remove non-boundary lines and
any text that's vectorized. |
| Step 7. Use Vector/Create Polygon Layer to create polygons and use
Edit/Line Editor/Form Polygon to close polygons if needed. |
| Step 8. Assign IDs to parcels if needed and export the
vector data. |
