typedef enum lmrcImageDensityChangeEstimationMode {
mrcImageDensityChangeEstimationCentreOfGravity =2,
mrcImageDensityChangeEstimationMax =4,
mrcImageDensityChangeEstimationCentreOfGravitySD =8,
mrcImageDensityChangeEstimationMaxSD =16
} lmrcImageDensityChageEstimationMode;