Visual Inspection of Bakery Products by Texture Analysis

The appearance of bread, such as colour and visual texture are important to the consumer when purchasing bread. The perceived colour of bread is a function of its solid-phase crumb, air-phase and viewing conditions, varying with age and ambient lighting. Visual texture aspects include the alignment of fibres with respect to the axis of view and the distribution of small fat regions in both phases. Texture analysis on bread on the other hand is somewhat more subtle. A close inspection of bread stuff reveals that the bread-crumb texture comprises two phases of material; the solid-phase crumbs appear connected, while the air-phase crumbs are scattered randomly at isolated regions. In general, the thickness of the cell walls affects grain quality greatly. Thin cell walls are more prevalent in fine textured crumbs, and thick cell walls are generally found in coarse crumbs. It can also be seen from these figures that the distribution of phases within the crumb structure may be irregular, but the volume fraction properties are statistically and essentially homogeneous. Thus the overall textural properties of the bread crumb can be studied from images taken from different regions of a whole bread-crumb specimen. In the proposed work, a 2-D Haar transform together with canonical discriminant analysis is used for texture analysis in bread stuff in bakery industries.