If you use a wrong algorithm, that can be a case. For example, when you use bilinear interpolation to "down-size" image, for large image, you can end up interpo

If you use a wrong algorithm, that can be a case. For example, when you use bilinear interpolation to "down-size" image, for large image, you can end up interpolating between two far away pixels whereas if you use a smaller image, the two pixels you use are already averaged (interpolated), thus, can get a more pleasing result.