| iTool User's Guide: Working with Images |

## iImage Tool Operations

The iImage tool provides the following operations:

### Viewing a Histogram

A histogram is a density plot showing a distribution of data values. To view a histogram of image data, use the iTool's histogram feature by selecting Operations Histogram. For information on histogram creation, see Plotting a Histogram.

### Viewing Image Statistics

To view statistics for image data or for ROIs, use the iTool's statistics feature by selecting Operations Statistics. For information on viewing statistics, see Displaying Statistics.

### Cropping Images

The iImage cropping operation allows you to crop one or more selected images at a specified location and specified dimensions. To activate the cropping operation, select Operations Crop. The Crop manipulator is automatically activated.

Figure 10-11: The Crop Operation Dialog

Figure 10-11: The Crop Operation Dialog

Note The appearance of this dialog can be disabled for future uses of the crop operation by setting the Show dialog property to False.

The X, Y and Width, Height properties in the dialog represent the location and dimensions of the crop box to be applied. If these values have never been set, they are by default initialized to match the full extent of your first selected image. If these values have previously been set, they are constrained to fit within the first selected image. You can enter new values manually, or the mouse can be used to define, resize, and/or translate the crop box.

The Units property can be set to indicate the units of measure to be used for reporting crop box coordinates. The default is data units. This property will automatically reset to data units (and become de-sensitized) if multiple images are selected and their pixel origins or pixel sizes differ.

Once your crop dialog is present on your image, you can crop by doing the following:

- Double-clicking anywhere within your defined crop box (in the primary visualization window).

- Pressing the Crop button within the crop operation dialog.

Once your image is cropped, the original image is replaced by the new, cropped image data. You can only retrieve your original data by selecting Edit Undo crop, or by reloading the original image data as a separate visualization.

Note If your original image contains any ROIs, those that do not lie completely within the crop box will be lost in the new image.

IDL Online Help (March 01, 2006)