3-D annotation volumes were updated in the June 2013 release to reflect changes in the atlas drawings and ontology. Also note that the volumes are now in a 32-bit format to large structure identifiers.
Three Four volumetric data files are available for download:
- atlasVolume: uchar (8bit) grayscale Nissl volume of the reconstructed brain at 25 µm resolution.
- annotation: uint (32bit) structural annotation volume without fiber tracts at 25 µm resolution. The value represents the ID of the finest level structure annotated for the voxel. Note: the 3-D mask for any structure is composed of all voxels annotated for that structure and all of its descendents in the structure hierarchy.
- annotationFiber: uint (32bit) fiber tracts annotation volume at 25 µm resolution.
- gridAnnotation - 200 100 µm: uint (32bit) combined structural and fiber tract annotation volume at grid (200 100 µm) resolution for gene expression analysisprojection analysis.
- averageTemplate: uint (16bit) average brain template used as registration target.
Volumetric data is stored in an uncompressed format with a simple text header file in MetaImage format.