X-ray computed tomography (XCT) with flat-panel matrix detectors is a promising non-destructive method to scan and characterize external and internal structures of a specimen. Using XCT, both size and topology of different types of heterogeneities may vary largely. The different size scales of the heterogeneities and of the affected material volume require appropriate tomographic methods, scanning geometries and resolutions. In order to quantify features of interest from XCT scans, a major challenge is still found in the analysis and visualization of the generated XCT data: Advanced 3D-image processing techniques are needed for robust extraction and characterization of each single feature of interest. Interactive visualization techniques are needed for further exploration and analysis of these increasingly complex data spaces in order to provide novel insights for domain specialists. As examples of how image processing and visualization complement XCT various application cases are presented.