I am shopping for a flatbed scanner. I want a scanner that can perform one step (one pushbutton) consecutive scanning that can preferably be set to create .png files. The scanner should automatically store the .png files titled in a consecutive order and saved automatically in a folder in the USB attached PC. Since I cannot get Cannon sales persons to answer this question. Does the CanoScan LIDE 300 and / or CanoScan LIDE 400 work in this manner?