The Viewer is the main QuPath component in which images are shown.
This section describes the controls and shortcuts that can enable you to use the viewer efficiently to move around images and draw annotations. If you would like to know more about changing how pixels are displayed (including adjusting the brightness and contrast), check out the Separating stains section.
Using a mouse (default mode)
Select the Move tool , then click on the image and drag to move it.
If another tool is currently selected, press Spacebar to temporarily activate the Move tool. Releasing the Spacebar returns to the previously selected tool.
Alternatively, to move quickly to a specific region simply click on the area you wish to navigate to in the overview shown in the top right corner.
Use the scroll wheel to zoom in and out.
The location of the cursor determines where will be centered whenever zooming - so it is a good idea to put the cursor on top of the area that you would like to zoom to.
If everything seems inverted:
In some cases, it may appear that scrolling makes things move in the opposite direction from what is expected. This can happen, for example, when using a Mac with Scroll direction: natural turned off in the System Preferences.
If this affects you, open QuPath’s Preferences panel () and change the setting for Invert scrolling. It should behave better afterwards.
Using a trackpad (or touch-sensitive mouse)
Of course, the mouse controls also work with trackpads. However additional touchpad gestures can be activated under. These can be used to turn on ‘pinch-to-zoom’, and free up the scrolling motion to navigate the slide. This can also enable rotation.
It is possible to use at least some of the gestures with a touch-sensitive mouse, e.g. the Apple Magic Mouse. For example, turning on the scroll gestures only provides an efficient alternative method to navigate images. Just don’t forget to hold down the Shift key when scrolling to zoom in and out.
Using a keyboard
Up / Down / Left / Right
For most images, scroll the image in the direction pressed. For a TMA image, select the next core in the direction pressed.
Shift + Up / Down
Zoom in or out.
The action depends on the object currently selected:
If an annotation is selected, a dialog box will be shown to set the annotation properties
If a TMA core is selected, a dialog box will appear to allow notes to be entered quickly
Otherwise, the viewer will be centered on the object (think: ‘center on enter’)
Temporarily turn on the Move tool (as described above).
Other input devices
Gesture controls can also be applied to touchscreens. Customize with.
If you have a compatible pressure-sensitive graphics tablet, QuPath’s Brush tool is able to adapt size according to pressure - with the help of an extension based on JPen.
So far, this has been tested only with Wacom tablets (Intuos and Cintiq).