Encord's Bitmask brush tool enhances the precision of image annotation, which is essential for training accurate machine learning models, by allowing users to interactively and finely select regions of interest within images. The tool assigns specific bit patterns to pixels as users brush over them, indicating their association with particular labels or categories, and offers functionalities such as selection size adjustment, label application, and the use of an eraser for refining annotations. Additionally, the Threshold brush, specifically for DICOM images, enables setting intensity value thresholds to better visualize and label image areas, while the Encord Bitmask SDK leverages Python libraries to generate, modify, and analyze annotations effectively within the Encord platform. Overall, Encord’s Bitmask brush tool offers an intuitive and flexible solution for image annotation, empowering machine learning practitioners to achieve precise results and enhance model performance through data-driven insights.