I want to compute an area of certain object on a picture using Monte Carlo method. The picture shows some shape on white background. To do so I figured out that I'd get the coordinates of non-white points and then I'd launch the rest of the routine in e.g. Excel. My problem however is that I don't know about any application or software that performs what I want - i.e. getting coordinates of pixels of some specified colour. Can someone suggest some application or software which can do what I want?
How do you want to do this? For example you can do it with a GIS software like QGIS or R.
with a GIS software, one way of doing it is to transform the raster to a shape file (point geometry) and keeping the value field (cell value). After you can extract the coordinates of each point that corresponds to the center of each raster cell.
In R you can use the Raster package with the function xyFromCell .