CDA - Creating Digital Artifacts with Images, Sounds, and Videos Lesson

Creating Digital Artifacts with Images, Sounds, and Videos

Before you download a song or an image to your computer, do you ever consider what you are really downloading? Remember everything in a computer is stored in binary code. So you are actually downloading a lot of 1s and 0s when you are dealing with images, sounds, and videos.  

Have you considered how much space those 1s and 0s require? The file size for all information is measured in how many bytes it stores.    

Below is a list of all the standard units of measurement used for data storage, from the smallest to the largest.  

a list of all the standard units of measurement used for data storage, from the smallest to the largest.  

Why do we need to be concerned about the file size of our multimedia?        

  • Computers have limited storage capacities so you want to efficiently minimize the amount of space the artifact requires.  
  • If you are sending a multimedia artifact through email as an attachment, there are limits to the size of the file.    
  • Large files can take a long time to download or upload.  

Data Compression

Data compression is the process of reducing the size of files by compressing the data. It does this by encoding the information using fewer bits than the original representation. It identifies and eliminates redundant or irrelevant information and transforms the file into a smaller one. Compression can be either lossy or lossless.

Two Types of Compression

Lossless Compression

Data compressionLossless data compression reduces the file size without any loss of data quality. A lossless compression recovers the data exactly as it was upon decompression of the file. The decompressed file is an exact replica of the original one. Lossless compression is used when it is important that the original and the decompressed data be identical. Lossless compression is used when you create a ZIP file. A zip file contains one or more files that have been compressed. ZIP files have the extension .zip and must be extracted before the files can be used.

Lossy compression

Lossy data compression is a method of encoding that uses approximations, or partial data, for representing the content of the information encoded. It enables even greater reductions in file size by removing some of the bits that are irrelevant and not necessary. Usually, a certain amount of data reduction is needed before the result is sufficiently noticed by the user.  Lossy compression is most commonly used to compress multimedia data such as audio or video and still images. It removes irrelevant information so it is least noticeable.

Below is a list of file type extensions for different media for lossless and lossy compression.  

3 types of media - images, audio, video

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