Large Volume Display

Image-Pro with 3D Module only

The Large Volume Display handling is available only with Large Volume license.

The purpose of this functionality is to enable visualization of large volumes that cannot fit into computer RAM or GPU RAM. The way to visualize these files is to create separate files in pyramidal, multi-resolution format and load only portions of the file with optimal resolution that are visible at the given moment in 3D view.

Implementation of this functionality requires generation of Large Volume Files.

Automatic generation of Large Volume Files

When a large volume is loaded for first time to 3D view, a background command starts generating large volume files for every channel of the volume.

The Volume Display group of the 3D View ribbon provides controls for reloading the image with different sub-sampling and/or voxel size settings. It also has controls that allow you to store and retrieve entire sets of 3D View selections and settings.

The Large Volume file generation is done in the background, so the user can interact with the volume and do other operations without interruptions. If necessary, the file generation process can be canceled in the task manager.

As soon as the Large Volume File is generated, it will be loaded to 3D view. The Volume Display group on the 3D View ribbon shows asterisks for X, Y and Z sub-sampling as an indication that the volume is loaded from LVF. When a volume is loaded from LVF the resolution of the image is gradually gets refined with time after every interaction. It may take a couple of seconds to display the view at full resolution.

Large Volume Handling options

The Image-Pro Options dialog has a page with the options related to Large Volume Handling. The page include the following subsections:

  • General
  • File Generation
  • Volume Visualization.

General

The Enable Large Display Volume Handling checkbox in the General section enables/disables the LVE feature. When the option is disabled, Large Volume Files are not generated automatically and not used for visualization.

File Generation

The Show file generation info control defines the type of the info message that is shown generating LVF when the volume is loaded to 3D view. The choices are: Balloon, Warning Bar and None.

Auto generation size threshold defines the size of volume channel in Mega Bytes above which Large Volume File will be generated automatically at the first load to 3D viewer.

Large Volume Files folder defines the location of Large Volume files. By default the location is set to the application Images folder. The user can modify the location by typing the path manually or using the browse “…” button. When the checkbox Use source image folder is activated the LV files are generated in the folder of original image files.

Note, that when a volume is loaded to 3D view, the program is looking for LV files first in the source folder of the images, and then in this folder.

The user can open the folder and delete/copy/move LV files by clicking the Open Large Volume Files folder in Windows Explorer button.

It is possible to convert multiple image files or active document to LV file without loading them to 3D viewer. The user can do so using the Convert image files to Large Volume Files or Convert Active Document to Large Volume File buttons. Note that the conversion will be done in a background thread, so you can use the application without interruptions.

Volume Visualization

The Resolution parameter defines the resolution type for visualizing large volumes. The user can select Variable or Fixed resolutions.

  • Variable - default resolution type when volume visualization is fast and gradually increases with time.
  • Fixed- fixed resolutions (100%, 50%, 25%), should be used only for volumes that can fit into the memory, can be slower as it requires loading the whole volume at the selected resolution at once. Fixed resolution can be used for creating screenshots and animations to ensure that every frame has the defined resolution.

If the Use default CPU memory percentage is checked then system automatically defines the percentage of the memory used for loading volume tiles. The CPU Memory limit control defines the maximum amount of memory in the percentage of available memory used for loading volume tiles.

If the Use default GPU memory percentage is checked then system automatically defines the percentage of the memory used for volume virtualization. The GPU Memory limit control defines the maximum amount of memory in the percentage of GPU memory used for volume virtualization.