Grid automatic vectorization

Automatic vectorization of grid-deleted data can greatly improve the efficiency of Raster to Vector. The mode of grid-to-vector conversion is mainly applicable to grid-deleted data with clear lines. The specific operations are as follows:

Step 1: Import

Import Image Data to be vectorized, either as raster or as Image Data.

Import Image Files

Step 2: Registration

If there is no space Position Info in the imported Raster Data, in order to give the position of the actual ground object space to the scanned Raster Data, it is necessary to register it and correct the coordinates and projection of the grid map so as to make its coordinates accurate. At the same time, registration can also correct the image distortion caused by various factors during scanning. For a detailed description of the registration function, please refer to the Registration topic.

Step 3: Raster Binarization

If the lines of the Raster Data are clear and concise, binarization processing is not required, otherwise binarization processing is required through Raster Algebraic Operation: first, observe the difference between the lines in the Raster Data and the background value, and set a threshold, for example, If the grid value of all lines is greater than 10000 and the background value is less than 10000, the grid algebraic expression Con (dem & gt; 10000, 1, 0) binarizes the background and line values to 0 and 1.

Step 4: Grid Auto Vectorization

  1. On the Spatial Analysis "tab, in the Raster Analysis" group, click Vector-Raster Conversion "Drop-down Button, Select Raster to Vector "Options to bring up the Raster to Vector" dialog box.
    2. Select the Raster Dataset to be vectorized
  2. in "Source Data". For the binarized Raster Data, select the binarized Dataset.
  3. In the Result Data "area, select the Datasource where the Result Dataset is to be stored, select the Result Dataset type, Can be a Point Dataset, Line Dataset, or Region Dataset, and set the name of the Result Dataset.
  4. If line is selected as Result Dataset type, the corresponding parameters of result line data can be set as follows:
    • Smooth Method: It is only valid when the grid is converted to vector line data. SuperMap provides two Smooth Line methods, "B-Spline Method" and "Angle Grinding Method". If you want to know more about the smoothing process, you can refer to the Description of the smooth method documentation.
    • Smoothness: It is only valid when the grid is converted to vector line data and the "Smoothness Method" is not "No Smoothness". The valid value of Smoothness is related to the Smoothness Method. When the Smoothness Method is B-Spline Method, Smoothness will not be Smoothened if its value is less than 2; When the angle grinding method is used, the value of Smoothness is set to Is no less than 1. The higher the value of Smoothness, the smoother the resulting vector line.
    • Thin Raster before Conversion: If this option is selected, Raster Data will be refined before vectorization. Thinning reduces the number of cells in Raster Data that identify linear objects, improving the speed and accuracy of vectorization. For example, a scanned contour map may use 5 or 6 cells to display the width of a contour line. After refinement, the width of the contour line is displayed in only one cell. You can also refine the Grid/Image data in advance and then vectorize it. For an introduction to the Raster Thinning feature, see Raster Thinning.

The parameters in the
  • Raster Settings section take effect only when the Raster Dataset is vectorized, not when the Image Dataset is vectorized.
    • No value: For Raster Dataset, the cell whose pixel value is set for this value is regarded as no value data and does not participate in the vectorization process.
    • No Value Tolerance: If the "No Value Tolerance" value is set after the "No Value Data" is set as the pixel value, the pixel value of the "No Value Data" and the pixel value within the tolerance range are regarded as the data unit that does not participate in the vectorization process.
    • Grid Value Field: Used to store the grid value of each cell in a field in the Result Dataset. The name of the grid value field is specified in the following text box. The default Field is value.
    • Convert Specified Value Only: Only the area where the cell value is equal to the set value is extracted for vectorization.
      • Grid values: Pixel values participate in the vectorization process for the cells for which this value is set.
      • Grid value tolerance: Set the tolerance range of the specified "grid value". Grid values within the specified "grid value" and floating tolerance range participate in the vectorization process.
    • The parameters
  • in the Image Settings section take effect only when the Image Dataset is vectorized, not when the Raster Dataset is vectorized.
    • Background color: For Image Dataset, if a cell of this color is encountered, it is regarded as the background color and does not participate in the vectorization process.
    • Background Color Tolerance: After the background color is selected for the Image Dataset, if the RGB value of a cell in the Dataset is within the floating tolerance range of the background color, the cell is also used as the background color and does not participate in the vectorization process. The tolerance value corresponds to three values of RBG at the same time. For example, if the tolerance value is 10, then the color value within the range of color values (R ± 10, B ± 10, G ± 10) is within the tolerance range, and the tolerance value range is (0 ~ 255).
  • Click the OK button to execute the vectorization operation, and click the Cancel button to cancel the operation.
    • Figure: Raster to Vector Result.

    Note: The results of automatic conversion usually need to be partially adjusted manually, and the Result Dataset can be edited by adding, deleting and modifying through the "Object Editing" function. Please refer to the Object Editing section for specific operations.