MGMT 1000 Lecture Notes - Lecture 8: Color Management, Data Compression
MGMT 1000 Tutorial 8 Notes – Pixel Coordinates
Introduction
• The actual pixel coordinates, pixel (row, column), do not need to be stored with their
values, because the pixels are stored in order, and the number of rows and columns is
known.
• The actual data value representing a pixel could be as simple as one bit, for an image
that is black and white (0 for black, 1 for white, for example) or quite complex.
• Each pixel in a high-quality color image, for example, might consist of many bytes of
data
• A byte for red, a byte for green, and a byte for blue, with additional bytes for other
characteristics such as transparency and color correction.
• As a simple example, look at the image shown
• Each point in the photograph on the left is represented by a 4-bit code corresponding to
one of sixteen gray levels.
• For this image, hexadecimal F represents black, and hexadecimal 0 represents white.
• The representation of the image shown on the right indicates the corresponding values
for each pixel.
• The storage and processing of bitmap images frequently requires a large amount of
memory, and the processing of large arrays of data.
• A single color picture containing 768 rows of 1024 pixels each, (i.e., a 1024 × 768 image)
with a separate byte to store each of three colors for each pixel, would require nearly
2.4 megabytes of storage.
• An alternative representation method that is useful for display purposes when the
number of different colors is small reduces memory requirements by storing a code for
each pixel, rather than the actual color values.
• The code for each pixel is translated into actual color values using a color translation
table known as a palette that is stored as part of the image metadata.
• This method is discussed
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