To start markup we should import images at first. Just press the “Import Images” button and select them (use "Shift" + "Command" buttons for multiple selections). You can also drag and drop images to the Images Pane to import them. MakeML converts all images to .png format with max 600x600px dimension. That's because computer vision neural networks for mobile devices usually work on low image resolutions.
Then let’s add annotation title. At this tutorial, we will make a model that detects moons. Enter "moon" in the “Add Annotation Title” field and select any color. Press button with a plus icon. So, we are ready for the markup.
You need to press the left mouse button to start annotation. Then you'll need to move around the object and left-click in key points of the object. To end annotation you need to press the enter button. If you want to cancel annotation creation you need to press the escape button.
So you are ready for training Neural Network.