| iTool User's Guide: Operations Properties |

## Region Grow Properties

Region growing expands a selected area to include nearby pixels that fall within a threshold range of the current selection. See REGION_GROW for additional details. For a description of how a particular control is used, refer to Property Controls.

Table C-30: Region Grow Operation Properties

Table C-30: Region Grow Operation Properties
Property | Control Type: Options
--- | ---
Region grow method | String List: The method used to select pixels that are similar to the current selection. Choose from these values: By threshold: The expanded region includes neighboring pixels that fall within the range defined by the Threshold minimum and Threshold maximum values. By standard deviation: The expanded region includes neighboring pixels that fall within the range of the mean of the region's pixel values plus or minus the given multiplier times the sample standard deviation as follows: `Mean +/- StdDevMultiplier * StdDev` where `Mean` is the mean value of the selected pixels, `StdDevMultiplier` is the value specified by the Standard Deviation Multiplier property, and `StdDev` is the standard deviation of the selected pixels. Default = By threshold
Pixel search method | String List: Specifies which pixels should be considered during region growing. Four-neighbor searching searches only the neighbors that are exactly one unit in distance from the current pixel; Eight-neighbor searching searches all neighboring pixels. Choose from these values: 4-neighbor 8-neighbor Default = 4-neighbor
Threshold to use | String List: Specifies the threshold values to use. Choose from these values: Source ROI/Image threshold: Base the threshold values on the pixel values in the currently selected region. Explicit: Specify the threshold values using the Threshold minimum and Threshold maximum properties. Default = Source ROI/Image threshold
Threshold minimum | Number: The explicitly specified minimum threshold value. Default = `0`
Threshold maximum | Number: The explicitly specified maximum threshold value. Default = `256`
Standard deviation multiplier | Number: The number of standard deviations to use if the region growing method is By standard deviation. Default = `1`
For an RGB(A) image use | String List: If the image has separate color channels, use the selected channel when growing the region. Choose from these values: Luminosity: Luminosity values Red Channel: Red values Green Channel: Green values Blue Channel: Blue values Alpha Channel: Transparency values. Default = Luminosity

IDL Online Help (March 01, 2006)