The Aerial Image Recognition Challenge revolves around sorting different landscape images ranging from beaches, lakes, forests, meadows and more.
The data comes from parts of the data set (NWPU-RESISC45) originally used in the paper Remote Sensing Image Scene Classification. This data set contains 45 categories while we only kept 13 out of them as a first preprocessing.
This solution to the Aerial Image Recognition Challenge was developed using Jupyter over the course of 2 months. The group members were KHATER Yara, POBELLE Marion and SERRE Gaëtan.
We first used an instance of the REsNet50 model that is already trained on the ImageNet dataset. All pre-trained models expect input images normalized in the same way, i.e. mini-batches of 3-channel RGB images of shape (3 x H x W), where H and W are expected to be at least 224. The images have to be loaded into a range of [0, 1] (in order to have small weights for small data entries) and then normalized using mean = [0.485, 0.456, 0.406] and std = [0.229, 0.224, 0.225] (both mean and standard deviation with pixels). So we made our images look the same way as the images ResNet50 was pre-trained on. We obtained stable results for our loss and accuracy.
As the pretrained ResNet50 model was performing well, we decided to recreate its architecture but without any pretrained weights. Once again we obtained great results on loss and accuracy.