The TV output would be perfect if one could adjust the picture size infinitely variable. Unfortunately this is not possible because of technical reasons. The TV chips used are only able to produce pictures with certain sizes. TVTool supports three of them but in most cases no one matches your TV screen size exactly. To reduce this problem partly there is the resize function.

The principles are very easy. If we cannot adjust the picture size we adjust the window size on the desktop, so that the window fits perfectly on TV.

As an example I have used PowerDVD. Usually it looks like that on the monitor when PowerDVD runs in fullscreen mode.
On the TV a part of the picture would be lost at the borders if you use the fullscreen size of TVTool. That is because of the overscan of the TV system. If you would use the desktop size, you would lose less from the picture but mostly you still have black borders at the left and right of the screen.

Now the resize function comes up. When you press the 'Select window' hotkey during PowerDVD is the foreground window, it will look like this on the monitor:

The PowerDVD window is now reduced in size. Since the player was in fullscreen mode before you don´t see a title bar or a border, how we know it from other windows on the desktop. The size of the window can now be adjusted with TVTool.

By pressing the 'Show TVTool' hotkey you bring the tool in the foreground and you can use the arrow buttons to adjust the position and the size. During resize mode the taskbar is hidden, if no other window is in the foreground. To quit this mode just press the 'Select Window' hotkey again. When all adjustments are done you can store them on one preset by pressing the save button. Under the point 'Active window' you will see the name of the window which is selected for resizing.

The result is that the PowerDVD picture matches the TV screen size exactly. This works with other applications, too, like Pubs or an Internet Explorer window. It does not work with programs, which window is not scalable and must have a fixed resolution like games.