That happens because you are creating a thumbnail based on the thumbnail which is only 48x48 (if that makes sense).
Change your code to:
[ImageDescriptor(160,160)] public virtual Blob MyNewThumbnail{ get; set; }
The new blob will then be created from the source file, and not from the Thumbnail property.
Also, remember to run the "clear thumbnail properties" scheduled job, so that you will reset those properties that have already been generated
I actually tried this first place but it also gives a blurred thumbnail. According to your answer I did run the "clear thumbnail properties" scheduled job too. Still getting the same blurred thumbnail.
That sounds strange. Are you sure it's not cached? What happens if you create a new property with a different name?
Yes. Checked with browser cache cleared. Also created a completely new property with different width and height. still getting a blurred thumbnail.
Just tested with jpg, png and gif. It seems like only jpg images get blurred. This is not a huge quality drop but a slight different is visible in jpg images.
I have a class that extends 'ImageData'. There I have defined few thumbnail Blob properties for the different sizes.
Then I can request the particular image thumbnail in the URL. My problem is this generated thumbnail images look blurred than the original. Even the original image is with high resolution.
Why is that happening and how to fix it?