A method for the evaluation of symmetry of camouflage patterns was examined by texture analysis of images. The authors collected 18 types of geometric patterns as standard images and 135 types of camouflage patterns for evaluation. Original camouflage patterns were transformed into the binary images, and two characteristic values, contrast and entropy were extracted from a co-occurrence matrix of each image.
From the values of the contrast and the entropy, two types of symmetry were defined. One type of symmetry is reversal symmetry when the pattern was reversed from a positive image to a negative image, and another type of symmetry is rotational symmetry when the pattern was rotated 90 degrees.
In the evaluation of symmetrical goodness, ranking of geometric and camouflage patterns was synthetically carried out. All checkerboard patterns had high values and all fine stripe patterns had low values. The collected camouflage patterns had various values, and we could select some symmetrically good camouflage patterns.

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The transmission of ultraviolet (UV) rays through clothes was determined by varying physical factors. The authors have concerned on the influence on the density, i.e., the number of yarns per unit area (yarns/cm2), of clothes and number of twists of yarns. Results obtained are as follows:
1) The higher density of clothes and the lower number of twists of yarn, the lower UV transmission through clothes.
2) The higher density of clothes and the lower number of twists of yarn, the higher coefficients of absorption and scattering. It was found that the increase in the coefficient of scattering is more effective than that in the coefficient of absorption.
3) The apparent coefficient of absorption and scattering per yarn, determined from density of cloth, is decreased by increasing density of clothes.
4) Assuming that yarns in the thickness direction will shift to warp-or weft-direction by pressing the cloth, the number of yarns per unit area has been calculated. The coefficients of absorption and scattering of single yarn, which were calculated from the density thus calculated, are equal for samples of different thickness. These results enable us to perform a comparison of the transmission of ultra violet rays among various samples with different thickness.

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