So what is the difference in “potential” quality of CIF vs. 4CIF? Resolution quantifies only how close pixels or lines can be to each other and still be visibly resolved. A 4CIF image “can” potentially produce a better quality image then a CIF image because the more pixels used to represent an image; the closer the result can resemble the original.
It does not necessarily have to be the case though as 4CIF does not mention the amount or quality of the data to be displayed in the pixels. Accordingly, a CIF image filled with more bits and higher quality bits than a 4CIF image “can” and will produce better visual and audible results. Other considerations vis-à-vis bitrate need to be accounted for to determine the potential video quality.