I'm quite a newbie in GIS.
I need to compute (without using any existing lib/tool) the longitude & latitude (WGS84) corresponding to the a pixel, inside a (georeferenced) map image.
- the x,y coordinates or the pixel,
- the width & height (pixels) of the map image,
- the bounding box (lon/lat coordinates for the top-left, top-right, bottom-left & bottom-right vertices).
Intuitively I try to use longitude difference between top-left/top-right, in correlation with image width and pixel x to determine the corresponding longitude.
Please be open minded. I don't ask for a ready to use solution, but for documentation to understand the key concept required to do it.