A movie capturing the appearance of a JPEG image that is deteriorating due to new saving

Images in JPEG format are basically irreversible compression and degrade each time it is saved. It is difficult to understand the difference once or twice, but it will degrade to the extent that it can be recognized immediately by repeating saving. I will introduce the state of the image that is compressed and degraded little by little as summarized in the movie.

Details are as below.
A 20-second movie that deteriorates as new storage is repeated 600 times.
GENERATION LOSS | HADTO.NET


There is a clear difference in the vicinity of 4 seconds (about 120 times).


It is around 10 seconds (about 300 times). Plenty of granular feeling.


I can not see it anymore.


Eventually it looks like a sandstorm on the TV.


2009/04/19 22: 04 Addendum
This is not simply repeating JPEG saving with the same compression rate, but a movie connected images saved by gradually increasing the compression ratio. As the contents of the program, we change the value of 1 to 600 from the highest value of compression ratio: 1.0 to the lowest value: 0.0 (600/600 to 1/600) by using MAP class and setQuality method of JPEG, It seems that the compression ratio is gradually divided into 600 times in 600 loops and saved at a different compression ratio.

Also,ImageMagickThere was a reader who actually verified what would happen if you repeatedly repeat overwriting with the same compression rate using. Garbage is occurring something.

Lonely programmer: I feel that I have not seen the appearance of JPEG format degrading with new storage · livedoor Blog (blog)