¥Volume rendering
concepts:
²Goal is to create a 2D image
consisting of pixels
²Each 2D pixel is
obtained from data looking down line of sight into 3D volume:
²Each 3D voxel
contains one numerical value
²Voxel value
determines the brightness (or color) of that voxel --- if it is visible
²Voxel value
determines the opacity of that voxel:
åOpacity = 0 Þ Transparent (brightness does not contribute to image)
åOpacity = 1 Þ Opaque (nothing behind it along the line will be seen)
åIntermediate values
are translucent:
å
Opacity = 0.5 Þ 50% of voxel brightness is added to pixel; voxels farther down the line will
contribute to other 50% of pixel result
If we
looked directly from the subjectÕs right
to left, all the data along the white line
would contribute to one image pixel