Algorithm 1: Proposed Master-Slave Algorithm for detecting COVID-19.

Assume i = chest X-ray image, p = pre-processing Step 1: Read(i) Step 2: Perform p(i) 2.1 Resize (i) to 256 × 256 2.2 Normalize pixel values (i) 2.3 Data sampling Step 3: Feature extraction (pretrained models: DarkNet, VGG16, ResNet, SqueezeNet, DenseNet) Step 4: Optimization (freeze layers, learning rate by using optimization technique) 4.1 Finding the best learning rate (lr) 4.2 Retraining the model concerning lr 4.3 Data sampling Step 5: Performance evaluation Step 6: Comparison (state-of-the-art recent technique)