4.6.2 Resample

Basic Description: Resample changes the number of rows and columns in a tile. Values for new pixels can be either the average or maximum value of surrounding pixels. If you choose to increase your resolution by a factor of 2 (double the number of rows and/or columns, for example), the result will look exactly the same as the original. This is because the pixels have been duplicated, so one row or column is split into two. The new tile size can be specified by inputting the tile size in pixels (samples) or the pixel size in meters (or fractions of the distance unit you are using).
Technical Details: Resample uses a nearest neighbor resampling method when the sampling density is increased by a factor of 2. If sampling density is increased by other factors, then either an average or a maximum method can be used. When the resolution is decreased, the average or maximum values are used for the new, larger pixels. The maximum is sometimes best for resampling high resolution GPR slices, so that you can reduce sampling in the traverse direction, but not lose small anomalies with averaging.
Instructions: After choosing a selection method and making your selection on the survey, enter parameters in the following order (go to each section for details):
4.6.2 Resample

Resample Method

1. Resample Method
The average method uses averaging to create new pixels if their boundaries overlap more than one pixel. The Maximum method uses the maximum of all pixels for a new pixels. Average is often the best choice, but maximum works well for decreasing the number of samples because very small anomalies are diminished in the averaging process.

Size Setting Method

2. Size Setting Method
You have two different methods here to accomplish the same thing: change the output resolution of tiles. If you choose Set Tile size, you can specify the size parameters (below) in samples (number of rows and columns). If you choose Set Pixel Size, you can specify these parameters in meters (or whatever distance unit you are using).

Size Parmeters

3. Size Parmeters
If you chose the Set Pixel Size in the Size Setting Method above, then enter the new pixel size in meters (or feet, or whatever distance unit you are using). If you chose to Set Tile Size, the display changes to allow you to enter the New Tile Size in samples (pixels) (see example below).
Last Updated June 15, 2011