Dead pixels?

[me3gle]

Not really sure what happened but lately I'm noticing a lot of "green" pixels where you would expect to see "black" in video playback. Happens both while streaming and on downloaded videos played in VLC or QuickTime, etc.

iMac Retina 5k 27-inch late 2015, bought new in 2017 so about 4 years of use.

Attached is a photo taken from my iPhone.

Any thoughts or advice would be greatly appreciated.

Thanks!
Mike

 

[pmiles]

Looks like compression artifacts.

 

[Boyd01]

I agree, those don't look like dead pixels to me.

 

[me3gle]

Is there a remedy to it? It's not terrible but it's certainly distracting.