CNCSimulator Pro

user guide

8.5. Image Maker

(Version 3.0 and later)
Image Maker (found in the Tools menu) is a tool to create contours from images. This can be helpful when you want to create logotypes, texts and other things when the only source you have is an image file.
The quality of the output depends largely on the image quality as well as the parameters used for the operation.
Please note that Image Maker works best with high contrast image files (drawings, clipart, logotypes, cartoons etc.). When scanning a photo of a person or an object, very large files will be created that can create memory issues and slow down the program.
To load an Image into Image Maker, click "Load Image" in the File menu.

Play around with the Preprocess and Trace Options parameters and click on the Trace button for each change until you get the best result.
To send the traced result to SimCam, click on "Exit and send result to SimCam" in the File menu.


Here is an explanation of the parameters:


Highpass filter radius
Apply a highpass filter to the image. This filter is approximately Gaussian and non-directional. The effect is to preserve small detail while compensating for background gradients. The parameter is a radius (in pixels) which corresponds approximately to the size of details which should be preserved. More precisely, the filter is implemented by subtracting a blurred version of the image from the original image. The parameter is equal to the standard deviation of the blur. The output of the filtering step is a normalized image whose average brightness is exactly 0.5. The default filter radius is 4.
Gray level threshold
Set the threshold grey value for bilevel conversion. The parameter is a brightness value between 0 for black and 1 for white. Any pixels below this brightness will be converted to black (thus, smaller values of the parameter will lead to whiter output).
Blur radius
Blur the image. The effect is to smooth out fine details and to reduce visual noise in the image. The parameter is the blurring radius, and should be chosen small (1 is a good value to start with). This is implemented as an approximately Gaussian, non-directional blur with standard deviation proportional to the parameter. Blurring is applied after the highpass filter, but before scaling and thresholding. If this option is not given, the default is not to apply any blurring.
Invert image
Invert the input image. If this option is chosen, it is applied to the image before any other operation. It is used to deal with white-on-black images, such as photographs of chalk drawings on a blackboard. Note that the behavior of this option is not in general the same as inverting the output bitmap, unless the thresholding value is also inverted.
Scale the image by an integer factor parameter>0. Scaling is done after highpass filtering, but before the thresholding step. A scaling factor of 1 indicates that no scaling is to be done. Otherwise, interpolation is used to fill in the in-between pixels. If the output of mkbitmap is to be used as input to a tracing program such as potrace, a scaling factor of 2 is recommended. This preserved the right amount of detail for the tracing algorithm to work well. If a scaling factor of 1 is used, too much detail is lost. If a scaling factor of 3 or higher is used, the interpolation tends to "invent" detail which was not present in the original image, thus preventing potrace from doing a good job.

Trace options

Despeckle size
Suppress speckles of up to this many pixels.
Set the corner threshold parameter. The default value is 1. The smaller this value, the more sharp corners will be produced. If this parameter is 0, then no smoothing will be performed and the output is a polygon. If this parameter is greater than 4/3, then all corners are suppressed and the output is completely smooth.
Set the curve optimization tolerance. The default value is 0.2. Larger values allow more consecutive Bezier curve segments to be joined together in a single segment, at the expense of accuracy.