How to tackle different Image dimensions : I am working on a problem where I have to classify image into different groups . I am a beginner and working with Keras with simple sequence model . How should i tackle the problem of images with different dimension in below code e.g. some images have dimension 2101583 while some have 210603 etc . Please suggest .

model.add(Dense(100,input_dim = ?,activation= "sigmoid"))


model.add(Dense(100,input_dim = ?,activation= "sigmoid"))