Best way to remove these artifacts?

[Still-learning]

Been working on a somewhat older photograph and ran into these 'jpg like artifacts'


(the small horizontal & vertical lines)

I used Gaussian blur 0,3 but as I hate blurring I hope that someone has a good tip for this..

 

[colleague]

you can go to filter noise > reduce noise
or you can use filter noise > dust and scratches
but the best way is open the file in ACR (even if the file is a jpg) and use noise reduction in ACR

http://techfleece.com/2011/11/08/how-to-reduce-noise-in-images-using-adobe-camera-raw/

 

[Tom Mann]

Actually, the really best way to deal with JPG artifacts is to use software designed specifically to reduce JPG artifacts, e.g., http://www.topazlabs.com/dejpeg/ .

The problem is that (a) it's not free, and (b) it only works on images that haven't already been resized or otherwise manipulated (eg, contrast / brightness / color changes). The image you posted clearly has already been resized, and most likely otherwise manipulated. OTOH, if you have the original, you might be in luck.

If your image doesn't meet these criteria, then noise reduction algorithms can be used. The best are the fully adaptive ones like Neat Image. IMHO, NR in even the latest versions of LR / ACR has gotten quite good, but still isn't as good as some of the stand-alone NR plugins, especially on quasi-repetitive noise patterns like this. Fourier Transform algorithms are also quite good for this, but you really have to know what you are doing to use them and not simply make matters worse.

HTH,

Tom M