Image viewer

The image viewer displays an image. Left-click and drag to pan; mousewheel to zoom.

At the top left is the image’s minimap. You can click anywhere in the minimap to center the view on your click. Moving the mousewheel while on the minimap will modify the image zoom.

Directly below the minimap, several image statistics are shown:

  • Size is the total size of the image.
  • View is the position and size of the current viewport.
  • Zoom is the current zoom level. Mouseover the zoom indicator to open fine-grained zoom controls.
  • Pos is the current position of the cursor.
  • Col is the current RGB value of the pixel under the cursor.

Image viewer


The image viewer and differ have the same config, which allows setting the background color.

browse bar

Image differ

If you’d like to follow along, you can download our example zip file. It contains all the example files used throughout the manual.

The first step when comparing images is to align them. DiffPlug provides a pin-matching system for this purpose. Right-click on some distinct feature in one image and select Add pin in the pop-up menu:

place the first pin

Next, right-click on another distinct feature in the image and select Add pin from the pop-up menu.

place a second pin

Do the same thing on the other image to add the corresponding pins.

place a matching pin

When both images have the same number of pins, the Zoom Fit Both Zoom fit both button becomes the Match Points Match points button.

When you press the Match Points button, DiffPlug will scale and translate the right image so that its pins match those in the left image as closely as possible.

points are matched

Comparison tool

Once the images are aligned, they can be compared. There are two comparison modes, Adjacent Adjacent and Overlap Overlap.

comparison modes

In Adjacent mode you see both images side by side (as shown above). In Overlap mode one image is hidden behind the other. Overlap allows several different ways to compare the images: flipping, fading, and wiping.

overlap mode

Manual flip

In this mode you can flip between the two images by pressing [F]. You can tell which image is currently being shown by looking at the thumbnails. The thumbnail for the image which is currently being shown will have a prominent highlight.

Auto flip

In auto flip mode, DiffPlug will switch between the two images automatically. You can specify the frequency of their change using the Frequency slider.

auto flip


The main parameter here is fade (%). Enter a desired value in the fade field and press [Enter]. If you specify 0%, you will see the first image only. If you specify 100%, you will see the second image only. By entering any other value between 0% and 100% you will see both images ghosted on top of each other.



This mode is useful for clarifying the difference in each particular section.

With the Horizontal wipe, you can move the boundary between the image to the left and right.

horizontal wipe

With the Vertical wipe, you can move the boundary up and down.

vertical wipe