The standard term in contemporary internet vernacular to describe low-quality images is:
Potato
It sounds absurd, and it is, intentionally (we live in a very sarcastic ageš„), but this is the standard term on the web.
From the internet-trend documenting site KnowYourMeme's entry on the meme potato:
"Recorded with a Potatoā is a phrase commonly found in YouTube comments criticizing the resolution of a video that appears heavily pixelated or blurry.
From Reddit on the same subject:
It's ... a joke that their camera is so low tech, it's equivalent to a non technological item like a potato.
See also the B3ta website, where "potatoshop" or "potatochop" was often used for low quality image manipulations, often followed by someone exclaiming "Seamless!".
This was happening in at least 2003.
Google searches show it happening in like 2002.
The story behind it is that potatoes don't take very good photos.
The usage is so widespread that this high-quality image of a potato:
Credit to @Lawrence for finding this article
was bought by an Silicon-Valley internet-tech millionaire for over a million dollars. Ironically.
Welcome to the internet.
š„ Sorry for the potato-quality answer.