Loading the First Image Volume
MultiTracer version 2
The first image volume has the following special properties:
- No other images can be displayed until the first image volume has been loaded
- All subsequent image volumes must have the same dimensions as the first image volume and will
be discarded if they do not
- Loading a new first image volume will cause any other images to be discarded if they do not
match the dimensions of the newly loaded first image volume
- Only the first image volume can be edited or saved
Images must be in Analyze or NIfTI format. MultiTracer is able to automatically detect when the image headers and
images need to be byteswapped, so images from different platforms should automatically display correctly.
To load the first volume image:
- From the main MultiTracer window "File" menu, choose "Open First Volume ..."
- In the "Open" dialog box, choose either the 'Analyze File Filter' or the 'NIfTI File Filter' depending on which type
of file you want to open (Selecting the NIfTI file filter will also display Analyze format files since the .hdr suffix
is allowed for NIfTI files).
- Select the .hdr file or .nii file that you want to open from the "Open" dialog box.
If the file is not in the current directory, the popup menu in the upper left of the dialogue
box will let you move up the directory tree, or you can double click on a subdirectory icon to
move down the directory tree.
- If the file that you have selected is a supported data type, the x-dim, y-dim, z-dim, t-dim
x-size, y-size, z-size, bits/pixel and data type fields in the Open dialog will populate with
values from the header. If these fields remain blank, the file is not a supported data type
and any attempt to load the file will fail.
- If the t-dim of the file is greater than one, the "Load volumes" fields in the Open dialog
will be editable, allowing you to specify the range of volumes that you want to load (the
default is to load all volumes). Acceptable values for these fields range from one to t-dim,
and the value in
the first field must be less than or equal to the value in the second field. Editing is not
supported when multiple volumes from a single file are loaded into the same slot, so if you
want to be able to edit, both fields should specify the same volume number.
- Once the file is selected, click the "Open" button in the dialogue box to load the file.
- Large files may take several seconds to load; a status bar may appear to show your progress.
- Once the file is loaded, the image should appear in the display region. If no prior image has
been loaded, MultiTracer will
automatically take you to a plane in the middle of the image and will adjust the intensity of the
display to a (usually) reasonable value. If the display appears black, this may reflect a problem with
the automatic intensity adjustment, and you may need to set the intensity manually.
If you have already loaded a file and choose to load a new first image volume with different dimensions, any
tracings of structures will be discarded (you will be given a opportunity to save them first).
Nonetheless, it is always a good idea to save your traces
before you load a new image.
If you have previously loaded a file and choose to load a new first image volume with the same dimensions, you
will be given the option to discard or to retain any existing traces.
©2001-2012 Roger P. Woods, M.D.
Modified: August 27, 2012