Improving X-ray images of historically significant textiles.

• The inner information of historically significant textiles is essential for the preservation and restoration processes. • Radiography testing (RT) reveals hidden damage to under-sewing layers, clothing design and connections. • X-ray radiographs of the textile suffer from low contrast due to low density of the objects. • An image processing technique, e.g., Automatic Color Enhancement (ACE) methods has been implemented to improve the contrast of radiographs and reveal more information. • The conservators and radiographers can utilize this information for the restoration process. The availability of information as to the inner structures and condition of historically significant textiles and clothing items is essential for monitoring, preservation and restoration processes. Visual inspection is usually the initial step in identifying any damage, such as tearing or rotting, but it is not sufficient for examining of detail below the surface of the objects. Radiography Testing (RT) is a useful non-destructive approach, capable of revealing hidden damage to under-sewing layers, clothing design, and connections, providing crucial information for developing a conservation plan. However, due to the mainly low atomic number of the constituting elements of textile material and also the low thickness of such items, X-ray radiographs suffer from low imaging contrast, which is further compromised by noise due to the unavoidable detection of scattered X-rays, which introduces fogginess in the acquired radiographs. Using digital RT images as a starting point, two image processing approaches using histogram equalization and the more complex Automatic Color Enhancement (ACE) methods were applied to enhance the imaging contrast of the original radiographs. The results demonstrated the effectiveness of these methods in better identifying defects, hidden designs, motifs, and destructive regions within the inner layers of textiles. It was found that the ACE method produced better outcomes than the simpler histogram equalization approach. Results indicated that the ACE processed image could be favored over the simpler histogram equalization approach by its enhanced capability of targeted expansion of the scale for evaluation of deterioration. The conservators and radiographers were able to utilize the further and complementary capability towards improved object assessment, monitoring, and restoration procedures. [ABSTRACT FROM AUTHOR]