Brain tumor MRI image for Fedarated Learning

It is designed to support machine learning and computer vision research for robust, four-class brain tumor classification, particularly contributing to innovations in privacy-preserving federated learning and explainable AI (XAI) frameworks. Dataset Composition: The dataset is organized into four distinct, clinically meaningful categories based on pathology. ⦁Glioma tumor (2,547 images): MRI slices exhibiting glioma tumors. ⦁Meningioma tumor (2,712 images): MRI slices exhibiting meningioma tumors. ⦁Pituitary tumor (2,658 images): MRI slices exhibiting pituitary tumors. ⦁No tumor (2,500 images): Healthy, tumor-free brain MRI slices.

Preprocessing: ⦁Slices are harmonized to 224x224 pixels and loaded as single-channel grayscale images. ⦁A unified preprocessing pipeline was applied, including resizing, optional center/zero-padding, and per-image normalization to ensure consistency. ⦁For federated learning simulations, the dataset is pre-partitioned across four clients and further divided into an 80/10/10 (train/validation/test) split conducted patient-wise to prevent data leakage.