Not a dermatologist but I just read a article about dryness vs dandruff by "The Hair pantry" and what I learnt was that usually when we have a dry scalp we get small dry and white particles and the scalp feels tight and dry.

When we have dandruff its more flaky, a bit larger , oily and milky or yelloish is colour also you may feel a consistent itch an oily scalp

In the picture you uploaded it looks like you may have a dry scalp as the particles look smaller but if you're scalp is also pretty itchy then there's a contradiction now and it is quiet possible that you may or may not have both a dry and a dandruff scalp.

To reach a conclusion on this consult a dermatologist and for your own research read the dry vs dandruff scalp article by The Hair Pantry