Resolution is one problem in scientific image data acquisition. In observation of sunspot groups, we need to have enough resolvable detail to make out the proper features for sunspot counting and McIntosh classification. A lack of resolution may lead to lower estimates to the level of solar activity. As a result, some image processing measures are taken to improve resolution, however this tampers with the data.
A useful technique is to render an isophote of the image in order to make out details. Isophotes use pixel intensity to map out areas with different concentrations. This is usually used in mapping out topological terrain.
The software ImageJ allows users to construct 3D isophote rendering of sunspot groups. This helps make out points which are hard to see visually. Intensities can also be adjusted to make out fainter points.