Wednesday, August 3, 2011

Art Tech Tip: Tracing Low Resolution Bitmaps with Image to Surface Function

If you are having trouble getting a good trace (a Raster to Vector translation) on a low resolution bitmap, we have a new strategy for you to try. Using Mastercam Art, we will convert this image to a surface, smooth it out, and then slice the surface at a Z-depth to get a better trace.
Note: This strategy works best on low resolution black and white images.
Let’s run through this process using the following graphic. It is a low resolution image that is rather chunky, and we will process it with this new technique to get a good trace. Here are the steps:
  1. Convert the image to a surface. Select Create, Surface, Art Base Surface, From Image. In the Convert to Grayscale dialog box, select Maximize Contrast and Make Negative, then click OK. Note: In this image, we want the black lines to be raised. In this function, the whiter it is, the higher it is.
  2. In the Import Image Setting dialog box, set the height range to 0.08 and accept the changes.
  3. Create a rectangle around the surface.
  4. Select Smooth and select the rectangle.
  5. Input a Smoothing Radius at 0.045.
  6. Select Trace Art Model at Z Depth and set the slice depth to 0.003. This is the drop-down under Trace Image/Rast2Vec.
The completed trace is smoother and cleaner than the Trace Image result.

Because each image is different, the conversion process will also be different. What might work for one image may not be the best choice for the next raster image. This process works very well for grayscale (16 shades up to 256 shades), black and white, low-resolution bitmaps.

For a more detailed explanation of this process, please go to www.mastercam.com/art/techtip.pdf.