I guess this is potentially for this Kaggle competition:
I didn’t work much on this challenge but you can just resize your image with cv2.resize. It will create a pixel interpolation but the data representation should still be valid. You can also just copy the 75x75 image matrix at the center of a 224x224 matrix if you want to keep the exact pixel representation.
I tried that with resnet50 and it gave a top 20% result with a single model and without ensemble strategy.