So my after effects reduces the qulaity of an image and makes it really pixelated.
Although the image is clear when viewed in the footage tab in after effect but as soon as it is added to a compostion, it drops quality totally. And it affects the final render too. How can I solve this please?
They're "fine", but they're a fifth of your image size. See my previous reply. Perfectly normal under those conditions.
Not sure what you expect. You are scaling a 1500 x 3700 something image to a composition one fifth or even on sixth of that size. How would that not result in quality loss? You have a misunderstanding here. This is perfectly normal and would happen in any graphics program. You are working with pixel images, not vector content trhat re-rasterizes. Unless you considerably ramp up the sizes of your comps you'll always see this downsampling. It's computer math.
You are zoomed in 400% and are scaling a large image down. Of course you're throwing away a lot of info bay forcing AE to interpolate pixels. This isn't even a specific AE thing. It happens in every graphics program. You seem to have fundamentally wrong expectations/ understanding how this works. Also your composition appears super tiny if it doiesn't even cover the entire comp window at 400% zoom, so likely what you're doing there doesn't realyl make a lot of sense in the first place. Check the composition settings, work at 100% zoom.