1. Basic Concepts of Digital Imaging
Chapter Two
Basic Concepts of Digital Imaging

2. Resolution
Given a digital image of a certain size, the more pixels it has, the higher its resolution.
pixel = picture element
1 mega pixels = 1 million pixels
One measure of the visual detail contained in a digital image
In general, the more mega pixels a digital image has, the more detail it contain.

3. Example (640x480=307,200 pixels)

4. Example 5610x3627 = 20 mega pixels

5. Bit Depth
Bit depth--also called pixel depth or color depth--measures how much color information is available to display or print each pixel in an image.
Greater bit depth (more bits of information per pixel) means more available colors and more accurate color representation in the digital image.
For example, a pixel with a bit depth of 1 has two possible values: black and white. A pixel with a bit depth of 8 has 28, or 256, possible values.

6. Bit Depth
8-bit
4-bit
1-bit

7. 8 Bit vs. 16 Bit 8 bit gives 256 tonal values
It is likely that your digital cameras record images using 8-bit in the JPEG format.
More expensive digital cameras allow you to save images using 12/14/16-bit in the RAW file format. (example)

8. Color Modes Grayscale (Black and white) RGB (Red, Green, Blue)
Most common for digital photography
CMYK (Cyan, Magenta, Yellow, blacK)
Most common for (digital) printing
Lab
Reference color space for conversion

9. RGB vs. CMYK

10. File Formats JPEG TIFF RAW Convenient, compression, lossy
Lossless, large files
RAW
Proprietary (e.g. Canon’s CRW, Nikon’s NEF)
Large files
High bit-depth (e.g. 14-bit, 3 channels)

11. JPEG Quality