When you use Photoshop’s Save As feature (File > Save As) to output your work in JPEG format, you will be presented with the following Format Options:
Baseline (“Standard”): The image will be displayed line by line on the screen. This is the one to select for TourWriter images.
Baseline Optimized: Same as Baseline, but optimized further using Huffman coding
Progressive: You can specify 3-5 scans, meaning that it will have between 3-5 phases before it shows the final image.