Bless

• Analog data


  Continuous information, an infinite number of divisions exist between any two measurements
• Digital data


  Discrete, finite
• Digitization


  1. Sampling

  2. Quantization
• Digitizing media involves sampling and quantization regardless of the type of media: images, video, audio
• Sampling rate


  • Related to: image resolution, number of pixels in video, sampling rate of audio
• Bit depth


  • Related to: number of allowable colors in an image, number of allowable colors in video, number of allowable levels of amplitude in audio
• Bit


  Binary digit, has two possible values 0 or 1, 8 bits is a byte
• More bits can encode more information, but require more computer storage
• Prefixes (mega, giga)


  Used to represent large numbers of bits and bytes
• Converting decimal to binary

  Divide by 2, take remainders
• ASCII


  American Standard Code for Information Interchange, each character uses 8 bits
• Unicode


  Standard for encoding text characters, uses 16 bits per character
• Bitmap images


  Color value of each pixel encoded into bits
• Vector graphics


  Coordinates and tangents of anchor points encoded into bits
• Sampled audio


  Amplitude for each sample encoded into bits
• MIDI music


  Musical instrument and note IDs encoded into bits
• Lossy compression


  Some data lost, cannot be recovered (e.g. JPEG, MP3, MP4)
• Lossless compression


  No data lost, all information restored (e.g. PNG)
• Reducing sampling rate, bit depth, or applying file compression can result in loss or alteration of data, affecting media quality
• Cloud computing


  Computing model where software and files are hosted on a large group of interconnected computers accessible via the Internet
• Cloud computing service models

  • Software as a Service (SaaS)
  • Platform as a Service (PaaS)
  • Infrastructure as a Service (IaaS)
• Software as a Service (SaaS)


  Allows users to run software applications on the cloud via their devices
• Platform as a Service (PaaS)


  Allows users to deploy applications onto the cloud using supported programming languages, libraries, and tools
• Infrastructure as a Service (IaaS)

  Provides computing resources like processing, storage, and networks for users to deploy and run software
• Digitizing images


  The process of converting an analog image into a digital format
• Pixels


  • Discrete sample points that make up a digital image
  • Image resolution
  • Bit depth
• Bitmap images


  Images divided into a grid of pixels, each storing a color value
• Vector graphics


  Images generated mathematically, not pixel-based
• Aliasing


  The jagged appearance caused by under-sampling in rasterized vector graphics
• Anti-aliasing


  Techniques to soften the jagged appearance by using intermediate shades
• Increasing the number of pixels (resolution) increases the file size and detail of a digital image
• Reducing the bit depth (color depth) decreases the file size but may cause image quality degradation
• Lossless compression


  File compression that does not lose any information (e.g. TIFF, PNG)
• Lossy compression


  File compression that loses some information (e.g. JPEG)
• Common file types for editing/capturing digital images

  • PSD
  • PNG
  • TIFF
  • Camera RAW
• Common color models


  • RGB
  • CMYK
  • HSB
  • CIE
• RGB color model


  Additive color system, full intensities of red, green, and blue make white
• CMYK color model


  Subtractive color system, full intensities of cyan, magenta, and yellow make black

  
• HSB color model


  Hue, saturation, and brightness

  
• CIE XYZ color model

  Encompasses all colors visible to humans, but not used in digital imaging