Method for the correction of the measurements of optical density made on a radiographic film
AssigneeGeneral Electric CGR S.A.
InventorMichel Grimaud
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Abstract
To carry out an automatic processing operation on radiographic images in mammography, it is shown that it is possible to correct the harmful effects of the linearity defect of the characteristic curve of sensitivity of the radiographic film used for this radiograph by making a statistical study of the noise in this image. It is shown that this statistical study enables the correction elements to be deduced directly using a top hat transformation. The processing is then independent of any prior knowledge that might be had of the sensitivity of the film or of the conditions in which the examined radiographs were acquired as well as subsequently developed.
Claims12
A method to correct the measurement of the values of optical density of an image revealed on a radiographic film, the method comprising:
- a. measuring a value of optical density for each dot on the film, said measurement leading to a signal of optical density of the radiographed image;
- b. correcting said signal of optical density by taking into account non-linearities in the sensitivity of the radiographic film;
- and
- c. carrying out a top-hat transformation on said signal of optical density using a given size of structuring element on said signal of optical density.
Dependencies are inferred from the claim text.