Encoding and Compression
Over the past few weeks I have been converting Super 8 videos to my computer as well as scanning old pictures. During the process I have had a few hiccups and have had to explain encoding and quality degradation to a few people without success. I decided to do a little experiment and blog my results.
If I take a jpg picture and save it, without editing anything, 100 times will I lose any quality.
Here is my starting picture. (640 * 480 @ 43.9kb) (please note this blog may change the size on upload)
Here is the same picture after saving 10 times
Here is the same picture after 20 saves. It's quite obvious we are losing quality somewhere (no need to do the 100).
The reason for this is that jpg is a lossy compression format. Even when saving a JPG at the highest quality it is still compressed and has a slight quality loss. On the other hand TIFF and BMP are lossless formats saving each and every pixel of information. This is great but the file size can be cumbersome for the web.
If I take a jpg picture and save it, without editing anything, 100 times will I lose any quality.
Here is my starting picture. (640 * 480 @ 43.9kb) (please note this blog may change the size on upload)
Here is the same picture after saving 10 times
Here is the same picture after 20 saves. It's quite obvious we are losing quality somewhere (no need to do the 100).
The reason for this is that jpg is a lossy compression format. Even when saving a JPG at the highest quality it is still compressed and has a slight quality loss. On the other hand TIFF and BMP are lossless formats saving each and every pixel of information. This is great but the file size can be cumbersome for the web.
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