Input layer size is not matching with the image size in MTCNN

Question

I am using detector.detect_faces() function of MTCNN and getting following error -

detector = mtcnn.MTCNN() results = detector.detect_faces(pixels)

Input 0 of layer "model_6" is incompatible with the layer: expected shape=(None, None, None, 3), found shape=(None, 276, 375, 4)