Thursday, October 1, 2009

muddy point: wk 5


In TrueColor there is a bit depth of 24, which allocates 8 bits for each of three channels - Red, Green and Blue. Therefore, there are 2 to the 8th power, or 256, values possible for each of the three channels, and 2 to the 24th, over 16.7 million, possible values for each pixel when the three channels are combined. It was stated in class that digital images do not generally contain all of these values. It is now possible to produce digital images that use 16 or 32 bits per color channel, which would generate 2 to the 48th and 2 to the 96th potential colors respectively (is this correct?). Is this really necessary? Could anyone tell the difference? What possible applications would need such an insane number of colors? Are display devices even capable of reproducing that many colors? Are the compression rates of images with higher bit depth comparable to compression rates of lower bit depth images? If one were to use a lossy compression schema on a 48 bit image, would the loss in quality be less noticeable than on a 24 bit image?

A related question: is greyscale typically an 8 bit single channel with 256 values? Is the quality noticeably better if it is 16 bit channel?

A second set of questions: why is TIFF a better format for black and white images? How are tags applied or added to TIFF images - does one need a particular program to do it? Is basic technical metadata somehow added automatically?

1 comment:

  1. I don't know the answers to your muddiest point, but let me just say the pizza looks delicious.

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