A dual-view computer-vision system for volume and image texture analysis in multiple apple slices drying

• Volume/image textural features were measured with computer-vision system.
• Physical texture parameters and image texture features were measured with moisture.
• Volume was not a good indicator of the end of drying process.
• Eleven image texture features correlate well with moisture content (R2 < 0.9).
• Uniformity of intensity texture feature can predict the end of drying process.

The present study assessed the ability of a low cost dual-view computer-vision system (CVS) to measure volume and color co-occurrence image textural features of apple slices to find the end of drying process by comparing physical texture parameters and moisture content. Apple slices were dried at three different temperatures (40, 60 and 80 °C) and their volumes were measured with both the CVS and a caliper. The physical texture parameters and image textural features were measured according to the moisture content. While the CVS can be used to measure the volume of the apple slices during the drying process, the volume was not a good indicator of the end of drying because of porosity development. The peak force and initial slope of physical texture showed a significant correlation with H3, H5 and S2 and H3, H5 and S11 of image texture features, respectively. Eleven image texture features correlate well with the moisture content (R2 > 0.9) and also had a high correlation between each other. The uniformity of intensity (I1) of image feature was a good indicator of the end of drying because of the close correlations with moisture content. The drying times according to the moisture content and the uniformity of intensity were 4.31 ± 0.313 h and 4.42 ± 0.125 h, respectively.