3D Project ... Modification

3D Project ... Modification (Projector_TP)

Author: J. Anthony Parker, MD PhD (J.A.Parker@IEEE.org )

Dates: 2003/04/07: First version

Source: The source file, Projector_TP.java.

Installation: Download Projector_TP.class to the plugins or "plugins/NucMed" folder and restart ImageJ.

Description: This ImageJ PlugInFilter is a minor modification of the ImageJ class Projector (Image/Stacks/3D Project...). Five features have been added:

1. Depth cueing has been added to the mean value option. The cueing decreases the value of a pixel as a negative exponential function of depth. Reasonable values for this parameter are from 0 to about 1 or so.

2. "Z-Axis Orthogonal" has been added as a type of Axis of Rotation. The normals to the projections for the "Z-Axis" option are parallel to the z axis. The normals to the projections for the "Z-Axis Orthogonal" option are all perpendicular to the z axis. In Radiology, given an axial stack, this option makes projections around the patient. This same operation can alternately be performed by switching the stacks orientation (for example with To_Coronal) and then using the "X-Axis" or "Y-Axis" options. The mean value option with this option projects the pixels using non-integer weights in order to remove the vertical strips which can appear at some angles with some images. The other Axis of Rotation options retain the original nearest neighbor algorithm.

3. The inverted look up table message has been removed. In some cases projecting a stack with an inverted look up table makes sense; however, the user should be aware that inverting an image can produce unexpected projection values. If this PlugInFilter is installed with argument "LUT_WARNING" (or any argument with "warn" in it), the warning message is restored. The LUT on the projected stack is inverted to match the input stack only when there is no message. Thus, installing with the "LUT_WARNING" option produces the same behavior as the Project class.

4. An option to multiply the mean value by a constant has been added. In the case where there is sparse data (few pixels with high value) the mean can be very low. This option allow the user to compensate for this effect without compressing the number of gray shades.

5. An option to set the nearest point to the upper bound has been added. This option is useful for cases where the nearest point may be subject to varying amounts of partial voluming.

Author:	J. Anthony Parker, MD PhD (J.A.Parker@IEEE.org )
Dates:	2003/04/07: First version
Source:	The source file, Projector_TP.java.
Installation:	Download Projector_TP.class to the plugins or "plugins/NucMed" folder and restart ImageJ.
Description:	This ImageJ PlugInFilter is a minor modification of the ImageJ class Projector (Image/Stacks/3D Project...). Five features have been added: 1. Depth cueing has been added to the mean value option. The cueing decreases the value of a pixel as a negative exponential function of depth. Reasonable values for this parameter are from 0 to about 1 or so. 2. "Z-Axis Orthogonal" has been added as a type of Axis of Rotation. The normals to the projections for the "Z-Axis" option are parallel to the z axis. The normals to the projections for the "Z-Axis Orthogonal" option are all perpendicular to the z axis. In Radiology, given an axial stack, this option makes projections around the patient. This same operation can alternately be performed by switching the stacks orientation (for example with To_Coronal) and then using the "X-Axis" or "Y-Axis" options. The mean value option with this option projects the pixels using non-integer weights in order to remove the vertical strips which can appear at some angles with some images. The other Axis of Rotation options retain the original nearest neighbor algorithm. 3. The inverted look up table message has been removed. In some cases projecting a stack with an inverted look up table makes sense; however, the user should be aware that inverting an image can produce unexpected projection values. If this PlugInFilter is installed with argument "LUT_WARNING" (or any argument with "warn" in it), the warning message is restored. The LUT on the projected stack is inverted to match the input stack only when there is no message. Thus, installing with the "LUT_WARNING" option produces the same behavior as the Project class. 4. An option to multiply the mean value by a constant has been added. In the case where there is sparse data (few pixels with high value) the mean can be very low. This option allow the user to compensate for this effect without compressing the number of gray shades. 5. An option to set the nearest point to the upper bound has been added. This option is useful for cases where the nearest point may be subject to varying amounts of partial voluming.