A digital image represents visual information by discrete numerical data. In raster graphics, an image is an array of pixels, each carrying one or more channel values. A grayscale channel can encode brightness; a color image commonly stores red, green and blue channels. The encoding must specify how those numbers relate to color, rather than treating a channel value as a physical light intensity automatically.
An uncompressed image with three 8-bit channels uses bytes before headers and row padding. Increasing the pixel dimensions and increasing the number of representable channel values address different limitations: spatial detail and tonal precision. Data compression can reduce stored size without changing these nominal dimensions.
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A digital image is a representation of a two-dimensional image as a numerical grid of values. These values are typically organized in pixels, which are the smallest units that comprise the image. Each pixel contains information about the color or intensity at that specific point in the image. Digital images can be categorized into two main types: 1. **Raster Images (Bitmap Images)**: These images are made up of a grid of pixels, where each pixel represents a specific color.