Chapter 2 Flashcards
What does digitizing an image mean?
Converting an analog image into digital data that a computer can process.
How does increasing the sampling rate affect an image?
It increases image resolution, meaning more detail is captured.
What is resolution in digital imaging?
The number of pixels used to represent an image, typically measured in width × height (pixels).
How does higher resolution impact file size?
Higher resolution = larger file size because more pixels are stored.
Why does a lower sampling rate make an image appear blocky?
Fewer sample points result in less detail, making the image look pixelated.
What is a pixel?
A picture element, the smallest unit of a digital image that represents a single color.
Is a pixel a tiny square block?
No, a pixel is just a sample point, but it appears as a square when zoomed in.
What does pixel dimension refer to?
The width and height of an image in pixels.
What is quantization in the digitization process?
Assigning each sampled pixel a specific color value from a limited set.
How does quantization affect image fidelity?
Reducing the number of colors can result in loss of detail and color accuracy.
What happens if too few colors are used in quantization?
Different colors from the original image may be mapped to the same color, losing detail.
What is the relationship between quantization and bit depth?
Bit depth determines the number of colors available for quantization
What is bit depth in digital imaging?
The number of bits per pixel used to store color information.
How many colors can an image with an 8-bit depth display?
2⁸ = 256 colors.
What is the most common bit depth for digital images?
24-bit color depth, which supports 16.7 million colors.
How does increasing bit depth affect file size?
Higher bit depth = larger file size, since more bits are needed to store colors.
Why might increasing the number of colors in an image not always improve quality?
The selection of which colors are used is just as important as the total number.
What happens when an image has high resolution but low bit depth?
The image will have fine details but limited colors, leading to visible color banding.
What happens when an image has low resolution but high bit depth?
: The colors will be smooth, but the image will look blocky or pixelated.
What are the consequences of reducing bit depth?
The image may lose color variations, leading to posterization (a flattening of color gradients).
Why do digital cameras use high resolution?
To capture more details for better image quality.
What is the trade-off of high resolution and high bit depth?
Larger file sizes, requiring more storage and processing power.
