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Question and Answers

Question 51

Explain with examples the differences between additive color mixture and subtractive color mixture?

(Meyer, 1928).The world is full of colors. A human eye can distinguished as many as 16 million color By using only blue, red and green, all the other colors made from just three different colors .By using these three colors in different proportions, all other colors can be created (Meyer, 1928).Apart from these three colors not other color exist separately. So all the other colors are dependent on these three colors mainly. You may have learned the last time you printed a photo or chart from your computer. Most of us have probably had the occasional shock in such cases, wondering how a blue ended up as purple, and an orange as red. This experience illustrates one of the major problems with computer technology: as we move from images viewed on paper to those viewed on screen we cross a major technology boundary. Print documents use "subtractive color," made by mixing pigments. Objects absorb some wavelengths of light and what's left is what meets the eye. Add additional pigments, and additional wavelengths of light are subtracted from what you see.

Thus a blue object absorbs reds and greens, reflecting only blues. Computer and television screens have no pigments and do not absorb wavelengths of light. Instead, they use light-emitting phosphors, and produce different colors by mixing various wavelengths of emitted light. This type of color is called "additive" colour.Most scientific approaches to color involve development of a "color space" or a "color solid," a theoretical, three- dimensional model which aims to depict the range of all the possible colors. Such a color space must include not only all the colors, but all mixtures of colors, including mixing colors with white or black.

One obvious problem is that the difference between additive and subtractive color spaces is literally the difference between black and white. Add all of the subtractive primary colors together, for example, and you get black. Add all of the additive primaries together and you get white. Different color spaces also use different primary colors, and use different values to describe locations in color space (Bantick, 2002).

Not all colors in one color space have an exact duplicate in another. Thus, a printer may not be able to depict, in a book, a particular color you can see on your computer screen, because the computer's RGB color has no exact CMYK equivalent. We need a common standard for calibrating monitors and printers, and indeed many efforts have been made to do exactly that, but as yet there's no widely-accepted and widely-implemented standard (Bantick, 2002).

Question 52

Briefly describe the major principle of Bekesy's place theory of hearing?

(Meyer, 1928) The major principle of Bekesy's theory of hearing states that “which states that sounds of different frequencies set up different wave patterns in the cochlear fluids], and the piano theory.

Describe two types of evidence that support Bekesy's theory?

Bekesy's argument that this theory is incorrect because the basilar ...