The first step is trivial - we'll do grayscaling of the original image, since it will reduce amount of data to process, plus we don't need color information for this task anyway.
What is next? As we can see all glyphs are quite contrast objects - a black bordered glyph on white paper. So most probably a good direction is to search for black quadrilaterals surrounded by white areas and do their analysis. However, how to find them? One of the ideas is to try doing thresholding and then blob analysis for finding black quadrilaterals. Of course we are not going to use regular thresholding with predefined threshold since it will give us nothing - we simply can not set one threshold value for all possible light and environment conditions. Trying Otsu thresholding may produce some good results: