File menu
Image operations menu
Control points menu
Overlay menu
Options menu
Window menu
Using Toolbar
Registration is a recently emerged task in medical image processing used to match two independently acquired images. To register images, the geometrical relationship between them is to be determined. Matching all the geometric data available for a patient provides better diagnostic capability, better understanding of data, and improves surgical and therapy planning and evaluation.
Not always necessary for the registration itself but for processing and inspecting the results, a tool for displaying the image data is essential. We developed a Windows-based application which provides the following functions:
Image formats:
- 2D TIFF (input/output)
- Analyze (input/output)
- Viewnix1.0 (input only)
- microSegams (input only)
- DICOM (just a special part of it in this version)
More information on registration can be found at our page on registration methods.
All the necessary files can be found in reg380a.zip (214539 bytes). It contains the main executable regist.exe, two libraries bwcc.dll and ctl3d.dll, and two DOS programs called scanhead.exe and makehead.exe to help raw image conversion to Analyze format.
Installation is very easy: just put the files into the same directory and run regist.exe.
The program requires Windows 3.1 OS or newer.
The program is free to download and use, but is WITHOUT ANY WARRANTY! Use only at your own risk.
Please note that not all the functions are yet implemented and in several circumstances the program may crash.
We use the image format of the medical image processing program Analyze developed at Mayo Clinic, USA. Full description of this format can be found at Analyze home page.
In few words, Analyze format consist of two files. One header file (extension .hdr) containing the necessary information (e.g., dimensionality, size of voxels) and an image file (extension .img) containing the uncompressed raw image data. Our program can read 8-bits (unsigned char) or 16-bits (unsigned int) images. In the latter case, big-endian representation is assumed (note that PCs are little-endian!).
Having the raw image data, the header file can be generated using
makehead.exe.
Usage:
makehead.exe filename filetype x_dim y_dim z_dim x_size y_size z_size
File types (just use the corresponding number):
Content of a header file can be displayed by scanhead.exe.
File menu
- Open project, Save Project
The name of the two image files and the selected control point locations can be saved to and loaded from a text file.- Open base image, Open image to be registered, Save image
At the same time, two images can be loaded. One is the base or reference image, the other is to be registered. The currently active image can be saved to a new file.- Exit
Quits the program without any notifications (all unsaved changes, e.g., control points, image transformations will be lost).Image operations menu
- Edit transform matrix
The 12 parameters of a 3D affine transformation can be given explicitely. The dialog box will appear only when the image to be registered is loaded.- Set transformation
A rigid-body transformation can be given by setting translational and rotational parameters. The dialog box will appear only when the image to be registered is loaded.- Execute transformation
Execution of the transformation specified manually (using the previous menu items) or as the result of a point-based registration method. Note that the transformation will be applied to the currently active image.- Reslice image The size of the image and the voxels can be changed and the image will be resampled. Number of slices (Z-dim) will be calculated automatically. If you want to override this use the 'Explicit Destination Z-Dim' checkbox.
- Image upside-down
Reverses the sequence of slices.Control points menu
- Edit points
Currently selected point pairs will be displayed. Editing is not implemented.- Clear set #1, Clear set #2, Clear all points
Obvious.- Method
The desired point-based registration method can be selected.Overlay menu
- Palette, Mosaic
Fusion of the two images.Options menu
- System defaults
Defines the default display properties.- Image properties
Displays the name of the file, the dimension of the image, the voxel sizes, the minimal and maximal voxel values. An intensity window can be given (Min and Max to display). The first slice, the number of slices to display, and the zoom factor can be set.- 3D options
- Show histogram
- Gamma correction
- Overlay colors
Window menu
- BarTile, Tile, Cascade, Arrange Icons
Using Toolbar
Load base image and image to be registered.
See File menu.
Scroll slices
Click the icon then move the cursor to the image you want to change and press
- left mouse button to decrease the start slice,
- right mouse button to increase the start slice,
- shift + left mouse button to decrease the start slice by 5,
- shift + right mouse button to increase the start slice by 5.
Inc, dec slices to display
Click the icon then move the cursor to the image you want to change and press
- left mouse button to decrease the number of slices,
- right mouse button to increase the number of slices,
- shift + left mouse button to decrease the number of slices by 5,
- shift + right mouse button to increase the number of slices by 5.
Zoom in/out
Click the icon then move the cursor to the image you want to change and press
- left mouse button to decrease the zoom factor by 0.1,
- right mouse button to increase the zoom factor by 0.1,
- shift + left mouse button to decrease the zoom factor by 0.5,
- shift + right mouse button to increase the zoom factor by 0.5,
- ctrl + left mouse button to set the zoom factor to the maximum,
- ctrl + right mouse button to set the zoom factor to fit the window.
Change palette
Click the icon then move the cursor to the image you want to change and press left/right mouse button to select palette.
Select control points
Click the icon then move the cursor to the image in which you want to select points and press left mouse button to select a point and right mouse button the delete a point. The selected points and their number will be displayed (256 color are required - no more and no less). After selecting the necessary number of point pairs (usually 4 in 3D) or more, the registration error will be displyed on the Infobar. The required method can be selected at Control points/Method menu.
Select display mode
Click one of the icons then move the cursor to the image you want to change and press left mouse button to select the reference point. It sets the display mode to Transversal, Coronal, Sagittal, TCS (all-in-one), or 3D according to the selection.
Arrange windows
Tile, cascade, or bartile image windows (Window menu).
