Compressing documents & photos without loss of quality
(To Zip or not to Zip, that is the question)
One of our new members asked me today about possible loss of quality
if you were to reduce the size of a photo or compress it.
When your camera takes a photo, it will take it as a RAW image and
then will usually convert it and save it as a high quality jpeg image.
You will lose some pixels and hence some picture quality during this
conversion process … this is called a lossy compression.
So if you have an 8 megapixel digital camera, it will take an
8 megapixel raw image, and then convert it to a 3-4 megapixel
high quality jpeg image … so you will lose 4 million pixels in this
process, and lose some of the original quality.
Have a look at this Wikipedia entry for creating a ZIP FILE.
... where you greatly compress a large document or a large photo
down to a file which is much smaller. This is then easier to
send by email. The person who receives your email can then
unzip the file, and see the original document or photo without
any loss in quality.
To create a zip file … you could use either WINZIP or FREEZIP,
both of which you can download off the internet.
Freezip is free to use.
I don’t use zip files at all, as I find them too fiddly ... but they
are popular with some people.
Talk to you soon,
John
