1. Chapter 8: Digital Media
8.1 Learning Objective Checkpoints
2. Why are some digital audio files so huge?
Usually ithas to do with samplingratebecause ithas to do with sound quality.The better the sound quality,the
more spacethat is needed for it.
3. What is the difference between digital audio and MIDI?
Digital audio files contain digitized recordings of real performances,whileMIDIs contain instructionsfor creating
individual notes thatsound likevarious musical instruments.
5. How are images transferred from digital cameras to computers?
Card readers, directcabletransfer,infrared port, media transfers,dockingstations,or emails.Basically your
camera stores photos as bitmaps and bitmaps are produced by scanners and you can use them that way.
6. What affects the quality of a bitmap graphic and its suit-ability for Web pages, e-mail attachments, printed
photos, or desktop-published documents?
From what I could find on page 431,it said thatthe quality and suit-ability changes dependingon the use of the
bitmap.
7. Can compression play a role in reducing the size of graphic files?
Yes, however most graphic fileformats automatically compress files.You can do ityourself however. BMP files
shrink up to 70% whileimage files hardly shrink atall.
8. How do vector graphics differ from bitmaps?
They resize better, require less storagespace,not as realistic,and areeasier to edit.
9. Is it possible to convert vector graphics into bitmap graphics?
Yes, you can use itthrough a process called rasterization.
11. What affects the amount of video that can be stored on a hard disk or portable media player?
It is affected by the video format used on your camera. Video files produced from digital tapeusually arethe
largest,where videos stored on memory cards aresomewhat smaller and videos fromcell phones and webcams
are small enough to email.
12. How is digital video deployed on the Web?
They are embedded into the website.
15. How do digital rights management technologies restrict the ways in which I can use digital media?
They use a variety of technologies to do this.Authentication is a form of drm which allows contentto be accessed
only by authorized individuals.Copy rights arealso goingon which doesn’t allowvarious formats to existafter the
original format.Encryption also exists so thata filecan’t be viewed without a valid encryption key. Digital
watermarks areused so that the data can be tracked, identified and verified.
16. How are time shifting, place shifting, and format shifting related to digital media?
2. Time shiftingallowsa media to be recorded so that itcan be played back at a convenient time. Placeshifting
allows media started at one placeto be accessed from another placewithout changingthe device. Format shifting
is the process of converting media files fromone format to the other.
8.2 Beyond –the-Book Exercise
In this BTB exercise, you will be researching the concept of image propertiesand what theymean to the
field of digital forensics.
For this exercise download the following image located at the following link:
http://users.marshall.edu/~brunty11/geotag.jpg
Open the image using any available graphics software (or view the image properties In Windows). Use
this software to discover the properties (a.k.a. metadata) of the graphic. Indicate the source of the
graphic, then describe the its file format, file size, resolution, physical size, geolocation data, and what
camera it might have been taken from.
Source:Everyone (?)
File format: JPEG image
File size:1.48 MB (1,554,865 bytes)
Resolution:72dpi
Physical size:1936 x 2542
Geolocationdata:38;24;41.39 and 82;25;53.402
Camera:Apple IPhone 4
