This feature adds an alternative algorithm for producing projections. The FBP (filtered back projection) algorithm as it is traditionally employed in CT reconstruction applies the Ram-Lak filter to the projections and backward projects the result. This is the analytical inverse of the Radon transform. However, the filter produces negative values in the projection intensity.
This implementation of the algorithm adds to the filtered projections the absolute value of the minimum (negative) intensity offsetting all projections to have minimum value of zero.
This feature adds an alternative algorithm for producing projections. The FBP (filtered back projection) algorithm as it is traditionally employed in CT reconstruction applies the Ram-Lak filter to the projections and backward projects the result. This is the analytical inverse of the Radon transform. However, the filter produces negative values in the projection intensity.
This implementation of the algorithm adds to the filtered projections the absolute value of the minimum (negative) intensity offsetting all projections to have minimum value of zero.