v3dlib library is a cross-platform C++ library written in wxWidgets for displaying 3D images. The most important part of the library is a window that can display 3D images of various types (RGB, RGB16, GRAY8, GRAY16, and float). The window can easily be extended of a new functionality and is used in many applications (e.g., viewer3d, Acquiarium, batchcrop, and others).

The main purpose of this article is to provide basic information about the 3D window and its efficient usage. The article describes also the functionality that is accessible only from keyboard.

The main window contains three projection windows - xy, xz, and yz. Each projection window can display either orthogonal projection or maximum intensity projection. The type of projection in all windows can easily be changed by command View->Auto Focus.

Information about the loaded image is available in info window (Press “i”). It contains several tabs (Pixel info, Image info, and View info). "Pixel info" tab shows information about the voxel under the mouse pointer. "Image info" shows parameters of the loaded image: its type, size and voxel size and "View info" tab informs you about the current view.

· Bbox – information about the bounding box of the image (offset is usually zero and the size corresponds to the image size in microns).

· Visible – the portion of 3D space that is displayed in projection windows. It is always contained in the bounding box.

· Cut – current cut position. It is an intersection point of all three orthogonal cutting planes.

Remaining parts of this article show how to

· Change 3D cut position

· Move visible part 

· Change brightness and contrast

· Display greyscale images in colours

Authors

The library has been developed in the Center for Biomedical Image Analysis, Faculty of Informatics, Masaryk University, Brno, Czech Republic, by several people. The principal authors of the library are Petr Matula, Martin Maška, and Pavel Matula. Contact Petr Matula for more information about the library.