Scalpel is described as 'open source data carving tool' and is an app in the OS & Utilities category. There are more than 10 alternatives to Scalpel for a variety of platforms, including Windows, Linux, Mac, BSD and Google Chrome. The best alternative is TestDisk, which is both free and Open Source. Other great apps like Scalpel are PhotoRec (Free, Open Source), GNU ddrescue (Free, Open Source), DMDE (Freemium) and Foremost (Free, Open Source).
DM Disk Editor and Data Recovery (DMDE) is a disk editor which can help you to understand NTFS. Its capable to view your hard disk sector wise, on MFT level, to disect mft attributes and to edit bytes on your hard disk.
Foremost is a console program to recover files based on their headers, footers, and internal data structures. This process is commonly referred to as data carving. Foremost can work on image files, such as those generated by dd, Safeback, Encase, etc, or directly on a drive.
Extract images from PDF, PowerPoint, Word, Excel and other files. For Mac OS X 10.5 Leopard With File Juicer you can: Extract images from a PowerPoint slide show or presentation. Extract images and text from PDF files.
safecopy is a data recovery tool which tries to extract as much data as possible from a problematic (i.e. damaged sectors) source - like floppy drives, hard disk partitions, CDs, tape devices, ..., where other tools like dd would fail due to I/O error