Raster Reclassifying
Function Description
Reclassify the pixel values of the source Raster Data and assign values according to the new classification criteria, with the result that the original pixel values of the Raster Data are replaced by the new values. Raster Reclassifying works only with Raster Dataset (GRID), not with Image Dataset (IMAGE).
Raster Reclassifying is primarily used in the following four scenarios:
- Replace the old value of the pixel with the new value. For example, when the land type is changed, new pixel values are assigned to the wasteland that has been reclaimed as cultivated land.
- A large number of pixel values are regrouped and classified, and the pixels in the same group are assigned the same value to simplify the data. For example, dry land, irrigated land, arable land and so on are classified as agricultural land.
- Classify various Raster Data according to a unified standard. For example, if the factors affecting the site selection of a building include soil and slope, the soil type and slope of Input Data: Raster Data can be re-graded according to the grade standard of 1-10 to facilitate further site selection analysis.
- Some pixels which are not expected to be involved in the analysis are set to be valueless, or new measured values can be added to the pixels which are originally valueless, so as to facilitate further analysis and processing.
Function entrance
- Data tab-> Data Processing-> Grid-> Resize.
- Toolbox-> Data Processing-> Grid-> Resize.
Parameter Description
Resize List Tool Description:
- Range Settings: Select the Range Settings method for reclassification.
- Spacing: Each segment value is determined according to the spacing. When you enter a spacing, the system segments and increments the entered spacing value based on the minimum grid value up to the maximum grid value. The final segment value should be Less than or equal to the maximum grid value. For example, the minimum grid pixel value is 200. If the spacing is set to 200, the segment values are 200, 400, and 600; if the spacing is set to 300, the segment values are 200, 500, and 800.
- Number of levels: Determines the number of levels for re-classification. The default value is 10. When you enter a level value, the system automatically calculates each segment value in arithmetic terms based on the maximum and minimum pixel values in Raster Data. For example, if the minimum value of the Raster Dataset pixel is 200, the maximum value is 1000, and the input level is 4, the values of each segment are 200, 400, 600, 800, and 1000, respectively.
- When Number of Steps is checked and set, you can select Equal Interval or Natural Interval in Segmentation Method for classification.
- Default Class: Default system classification mode.
- Union Multi-line: The selected multiple consecutive records can be merged into a new record. From is the minimum pixel value in the selected original record, and to is the maximum pixel value in the selected original record. When only one record is selected in the table box or multiple discontinuous records are skipped, the consolidation segment value function is not available.
- Split line: a selected record can be split into two new records, and the pixel value of the original record will be divided into two equal parts according to the size of the value, which will be assigned to the two newly generated records respectively. The Split Segment Value function is not available when more than one record is selected in the list box.
- Import Raster Reclassify Config File: The re-classification Config File in *.xml format can be imported, and the program will re-classify the selected Raster Dataset directly according to the re-classification parameters in the Config File.
- Export Raster Reclassify Config File: The Classification settings in the list box and the Other Parameters Settings related to re-classification can be saved to a file in *.xml format. And is convenient to use again.
- Reverse ordering of target: used to reversely assign a new pixel value.
- Reclassify Type: Select the type of reclassification and provide Reclassify Range and Reclassify Unique Value.
- Re-classification List: The classification range can be customized. Each line corresponds to a subsection range, including From, To and target value. Details are as follows:
- From: the minimum value in each grading range after the pixel value of Raster Dataset is graded according to the set level.
- to: the maximum value in each grading range after the pixel value of Raster Dataset is graded according to the set level.
- Target value: The new pixel value assigned to all source pixel values within the segment range.
- Pixel Format: Sets the Pixel Format of the Result Dataset. The Application provides six Pixel Formats: 8-bit (unsigned), 16-bit (unsigned), 32-bit (integer), 64-bit (long), Single, and Double. The default value is 16-bit. Refer to the Raster DatasetPixel Format for a description of each Pixel Format.
- Range Interval: The open and close state of the Bounds Settings interval. Wherein the open interval indicates that the boundary value of the interval boundary is not included in the interval range, and the closed interval indicates that the boundary value of the interval boundary is included in the interval range.
- Left Close Right Open: The boundary value of the left boundary of the specified interval range is within the interval range, and the boundary value of the right boundary is outside the interval range.
- Left Open Right Close: The boundary value of the left boundary of the specified interval range is outside the interval range, and the boundary value of the right boundary is within the interval range.
- Null: For the null value in the source Raster Dataset, you can choose to keep the null value or set a new pixel value for it.
- Unclassified cell: Unclassified cell is the pixel value not involved in the re-classification list on the left side of the dialog box. You can select a new pixel value for its Uniform Settings.
- Result Data: Select the Datasource where the Result Dataset is stored, and set the name of the Result Dataset. Default is the same as Source Datasource.
Figure: Grid Reclass Result Comparison
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