Image Characteristics

Each image of the database has $70$ micron pixel edge and is stored using $12$ -bit word. Two different image sizes are possible: $2560 \times 3328$ or $3328 \times 4096$ pixels, and one size or the other is used according to the patient breast size.

The images are stored according to the DICOM standard [125]. Although different formats of storing the images are possible using this standard, in this case, they are stored in raw format: each number of the stored file corresponds to the grey-level value (from 0 to $4096$ ) of their corresponding pixel in the image.

Each case has its own annotations, including the breast density classified on BIRADS categories, the number of lesions, and if present a lesion, the location of its centre of masses and the minimum radius to evolve the lesion. Moreover, in the cases where the lesion is present, another image is stored in the DICOM which is a $1$ -bit-depth-image where the bit is 0 for pixels outside the lesion and $1$ for pixels inside or on the boundary of the lesion.