Arithmetic Operations
The Arithmetic Operations allows the user to perform operations on one or more images.  In addition to the operations that can be made between the bands of the images, it is also possible to apply gain and offset to the images. Some standard operations are defined in the interface:
 It is accessible through:
   Processing → Raster Processing → Arithmetic Operations...

  1. To use predefined arithmetic operations click on the icon . 
  2. Set the layer and correspondent bands and enter the gain and offset values
  3. Click on the OK button. The complete operation formula will be presented in the field below. 
  4. Check in the Normalize box and the values of the resulting image will be normalized
  5. Repository - Select one type of repository by clicking on the button to save the output layer as a file or on the button to save it in the database.
  6. Click on the OK button to start the operation.
The user can create customized arithmetic operations using layer selection and the calculator operations.
  1. Click on the icon an in the List of Layers select the raster layers to apply the operation. (Layer Search)
  2. Choose the band to operate and click on icon . Write the desired operation using the calculator keyboard.
  3. For future use the customized operation can be save by clicking in the icon .
Hint: For asin, acos and atan operations the values must be between -1 and 1.