You can change raster files in ArcGIS using various tools and methods, depending on what changes you want to make. Here are some common scenarios and their corresponding solutions:
1. Changing Raster Data Values:
- Reclassify: This tool allows you to change the values of raster cells based on predefined ranges or conditions. You can use it to simplify complex data, create binary maps, or change value ranges.
- Calculate Field: This tool allows you to perform mathematical calculations on raster values, such as adding, subtracting, multiplying, or dividing them. You can also use it to apply functions like square root or logarithm.
- Con: This tool allows you to combine multiple rasters based on conditional statements. You can use it to create a new raster based on specific conditions, such as selecting values from one raster if another raster meets certain criteria.
Example: You can use the Reclassify tool to change land cover classes from numerical values to categorical labels.
2. Changing Raster Data Resolution:
- Resample: This tool allows you to change the spatial resolution of a raster by interpolating values to a new grid. You can use it to create a lower-resolution raster for faster analysis or a higher-resolution raster for more detailed analysis.
- Aggregate: This tool allows you to combine multiple raster cells into a single cell, effectively reducing the resolution of the raster.
Example: You can use the Resample tool to create a lower-resolution raster for use in a web map.
3. Changing Raster Data Format:
- Convert Features To Raster: This tool allows you to convert vector data to raster data. You can use it to create a raster representation of points, lines, or polygons.
- Raster To Other Format: This tool allows you to convert a raster from one format to another, such as from a GeoTIFF to a JPEG.
Example: You can use the Raster To Other Format tool to convert a GeoTIFF raster to a JPEG for use in a web map.
4. Changing Raster Data Projections:
- Project Raster: This tool allows you to change the coordinate system of a raster. You can use it to align a raster with other data or to view the raster in a different projection.
Example: You can use the Project Raster tool to project a raster from UTM to WGS84.
5. Changing Raster Data Color:
- Colormap: This tool allows you to apply a color scheme to a raster. You can use it to visually represent different values in a raster.
- Symbology: This tool allows you to control the appearance of a raster in a map. You can change the color, transparency, and other visual properties of the raster.
Example: You can use the Colormap tool to apply a rainbow color scheme to a raster representing elevation data.
These are just some of the ways you can change raster files in ArcGIS. For more information on each tool, you can consult the ArcGIS help documentation.
