Image Processing Basics - Digital Signal Processing: Fundamentals and Applications - page 757

FIGURE 14.53

Reference frame, target frame, their difference, and the reconstructed frame by the motion vectors.

14.11 SUMMARY
1. A digital image consists of pixels. For a grayscale image, each pixel is assigned a grayscale level
that presents the luminance of the pixel. For an RGB color image, each pixel is assigned a red
component, a green component, and a blue component. For an indexed color image, each pixel
is assigned an address that is the location of the color table (map) made up of the red, green,
and blue components.
2. Common image data formats are 8-bit grayscale image, 24-bit color, and 8-bit indexed color.
3. The larger the number of pixels in an image, or the larger the numbers of the RGB components,
the finer is the spatial resolution in the image. Similarly, the more scale levels used for each pixel,
the better the scale-level image resolution. The more pixels and more bits used for the scale levels
in the image, the more storage is required.
4. RGB color pixels can be converted to YIQ color pixels. The Y component is the luminance
occupying 93% of the signal energy, while the I and Q components represent the color

information of the image, occupying the remainder of the energy.
5. The histogram for a grayscale image shows the number of pixels at each grayscale level. The
histogram can be modified to enhance the image. Image equalization using the histogram can