CompressionReasons of Compression Image Compression Settings .ppt

Compression Reasons of Compression
Image Compression Settings

1. Compression
Compression is simply the reduction of size of computer file.
There are two types of compression:
Lossy Compression
Lossless Compression

2. Reasons of Compression
•Attaching documents to emails
•Storing large files on a computer
•Transferring files on a storage device
•Speeding up download time of large files

3. Lossy Compression
•Lossy compression deletes part of the file,
reducing the file size, but when the file is
decompressed, the deleted parts cannot be
restored.

4. Lossless Compression
•Lossless compression prevents any data or
quality being lost when the file is compressed
and decompressed.

5. Image Compression Settings
•Following are adjusted when compressing an
image file.
•Colour Depth
•Resolution
•Image size

6. Run Length Encoding
RLE is a lossless compression method. It works by analysing
and reducing any repeated characters in a string by
grouping them together.
YYXXXXXXXYYYYYYYZZZZZZZZ
2Y7X7Y8Z

7. Run Length Encoding
RLE is a lossless compression method. It works by analysing
and reducing any repeated characters in a string by
grouping them together.
YYXXXXXXXYYYYYYYZZZZZZZZ 2Y7X7Y8Z
24 Bytes 8 Bytes

8. Image Data
•Requirement of:
•Image height and width in pixels
•The colour depth in bits

9. Compressing Image Data
bbbbbbw
bbwwwwb
bbwwwwb
bbbbbbw
bbwwwww
bbwwwww
Original Sting Size in Bytes RLE Version New size in Byes
bbbbbbw 7 6b1w 4
bbwwwwb 7 2b4w1b 6
bbwwwwb 7 2b4w1b 6
Bbbbbw 7 6b1w 4
bbwwwww 7 2b5w 4
bbwwwww 7 2b5w 4
Total file size 42 28

10. Cell Referencing
•Cell referencing allows
any piece of data,
across multiple
worksheets to be
referenced in a formula
or function.

11. Spreadsheet Formulas
Operators Description
+ Add
- Minus
/ Divide
* Multiply
= Equal to

12. Spreadsheet Formulas
Function Description
SUM Displays the total of a range of selected cells
AVERAGE Displays the average of a range of selected
cells
MIN Displays the lowest value in a range of cells
MAX Displays the highest value in a range of cells

13. Formulas and Functions

14. The effects of Technology on
environment
•The following are the major contributors to climate
change :
•Material Choices
•Energy Use
•Electronic Waste

15. Material Choices
•Increased use of technology means we need more
material to make them. Many of these materials are non-
renewable or very hard to recreate. For example:
•Precious material in circuit board such as gold and silver
•Sand , which is used to make glass and oil
•Aluminum, which used to create sleek product cases for
phones and other electronic devices

16. Electronic Waste (E-waste)
•E-waste describes devices that are no longer used and instead
of being recycled have just been dumped in landfill sites.
Problems caused by e waste include:
•Perfectly usable devices are not recycled
•Rare and toxic material can leak into the ground if devices are
not disposed properly
•Discarded electronics in landfill sites cab ve a health risk to
workers.

17. Preventing Environment Damage
Material Choices Energy Use Electronic Waste
•Reduce the need for rare
elements and focus or
artificial replacements
•Recycle the materials used
to manufacture devices
•Reduce the size and
thickness of devices
•Create more efficient
batteries that need less
charging and last longer
•Focus on renewable energy
sources such as solar and
wind
•Produce energy –efficient
devices that will hibernate
so that they save power
when not in use
•Create collection and
recycling points for
damaged /unwanted
devices
•Rehome unwanted devices
•Improve the upgradability
of devices, such as adding
memory rather than
replacing them

18. A B C D E
1Person Devices Total People =count(A2:A6)
201 3
302 2
403 1
504 5
605 3

19. A B C D
1 PersonOS Choice Number of Apple OS
2 01 Windows =COUNTIF(B2:B6,”Apple”)
3 02 Apple
4 03 Apple
5 04 Linux
6 05 Linux

20. Thank
you