This website applies some strange looking artifacts to the image during compression. When looking at the link to the original image, it is quite clean considering the low light hand held ISO 200 shot. I am new to the 640 LTE and an very please so far!
I took these pictures on the auto setting. The camera is very decent in most situations. You'll notice a lot of noise if you zoom in closely on pictures, but it's fine otherwise. Low-light is hit or miss, but that should be expected for a now $30 phone. The processing on pictures definitely gives them a pleasant quality, some may say over-saturated. Overall, I've been pleased since buying this phone last year.
I'm loving my new (to me) Lumia 640. After three years with a Lumia 1520, I much prefer the size of this device for just about everything except for watching Netflix and MyTube videos while in bed!