LO3 - Lesson 7 - File Formats

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EMS Creative iMedia
Cambridge Nationals

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LO3 - Lesson 7 - File Formats

  1. 1. File Formats Lesson 7
  2. 2. Lesson Goals  Know file formats used for images, audio and video  Understand the use of file compression techniques  Be able to describe properties and limitations of file formats #limitation #property
  3. 3. Viewing Digital Media What devices can we use to view digital media files?
  4. 4. Digital Media Know image, audio and video files Be able to describe file formats  Because there are so many different platforms which we can view images, video and audio we need different file formats depending on the device: #limitation #property
  5. 5. Digital Media Know image, audio and video files Be able to describe file formats  Digital media devices are required to be able to play back the following:  There are various different types of audio, image and video file and each one is used for a specific reason or type of job.  These different files will also vary in their quality, file size and the way that the file is compressed. #limitation #property
  6. 6. Image File Formats Watch the video and identify the good and bad features of five image file types: GIF PNG EPS
  7. 7. File Type EPS Not good for sharp edges Not great for text Some colour detail is lost when compressed Features millions colours No colours are lost No or little compression PNG Bad Points Zooming in is good quality Millions of colours Compresses well GIF Good Points Not compatiable with all applications Large file sizes Compresses well Very small file size Only has 256 colours Doesn't show all colours Millions of colours Compresess well Sharp edges Not compatiable with all applications Can only use in a few particular places Doesn't lose colour or detail Scalable to any size Does not lose any colour quality Can only open in certain software
  8. 8. Image Formats Know image, audio and video files Be able to describe file formats  Different image file formats are used depending on the way in which you want to use or display the image files but the quality varies greatly: JPEG GIF #limitation #property
  9. 9. What is compression? Think of what the keyword may actually stand for…
  10. 10. Compression Know image, audio and video files Be able to describe file formats  Digital media files can be either uncompressed or compressed: This is the original file which is at the best quality it could ever be. These files are usually used just for storage because they have massive file sizes. Compressed This is a file that has been made smaller to store on things like portable devices. They are poorer quality than uncompressed files but have a much smaller file size. #limitation #property
  11. 11. Compression Know image, audio and video files Be able to describe file formats  There are two main methods for compressing files: This technique uses a formula which doesn’t lose any of the original data so the quality of lossless compression files is good. Lossy This technique gets rid of any data it thinks is unnecessary. File sizes are much smaller but the quality is poor compared to lossless. #limitation #property
  12. 12. Your Task Know image, audio and video files Be able to describe file formats  Create a table showing properties and limitations of each image file:  Big or small file size?  Common file or not?  Where is it used?  State if the file is compressed or uncompressed. File Properties Limitations Compression #limitation #property
  13. 13. Key Words  File Format  The standard way that a digital media file is stored on a computer  Properties  Features of the file format such as the size and quality of the file  Limitations  Something that is a restriction on what you are doing or want to do  Compression  Making a file smaller for broadcast on different platforms

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