ABSTRACT
Since almost a decade ago, I have been involved in the study and understanding of the phenomena called visual appearance, which was added to the experience, almost 40 years, in subjects related to color. Color of foodssalted anchovy, beans, corned beef, noodles, apple juice, orange juice, milk sweet (dulce de leche), corn, apples, margarine, honey, ¤sh, sausages, tomatoes, wheat, wine, “yerba mate,” etc.—has been one of the subjects I studied while working at INTI, the National Institute of Industrial Technology, in Argentina. Ÿe present work intends to describe something more than color. In fact, it tries to establish a reasonable ground to understand a very complex phenomenon, such as the whole visual appearance, which includes color but is not restricted to it. It is well known that only three primaries are necessary to see color. We shall forget here to de¤ne which primaries we are dealing with. Presently, we accept that there are three primaries: red, green, and blue. Also, we shall not specify which these colors were. Now, when we see a texture, such as the skin of an orange or a lemon and the shell of a walnut, a peach, or a strawberry, color indicates not only the product but also the
2.1 Introduction 11 2.2 New Classi¤cation of Visual Appearance 12 2.3 Food and Its Glossy Appearance 15 2.4 Texture, Spatial Frequencies, Fractals, Wavelets, Fourier
Analysis, and Other Related Matters 16 2.5 Some Numbers to End 20 References 22
morphological characteristics of its surface and its visual appearance. Simply, to imagine the complexity of the problem, it is suÁcient to tell that up to six di•erent orientation angles can be set up relative to the horizontal de¤ned as 0° (90°, 60°, 30°, 0°, −30°, and −60°). To this, one must add what is called spatial frequencies, which are the lines of di•erent widths that we recognize as bar code used to identify commercial products in the supermarket paying boxes. It is supposed that only eight of these spatial frequencies are needed to identify its appearance e•ect. Ÿree colors, six orientation angles, and eight spatial frequencies make 144 variables, 144 possibilities. Ÿen, the question produces goose¨esh. If we have three di•erent detectors in the human retina, one for each of the three colors we see…, do we have 144 di•erent detectors systems in the retina to see form, color, and texture? Which are they? How do they work?
