====== Curtain ======
Curtain shows two to four images in one window at the same time, so that you can compare them. The images can be of any type (byte, integer or floating point), but they must all be the same size, with no more than 3 bands each.

===== Connecting the images =====
Connect the images to any of Curtain's four sides. In the arguments, choose which image goes in each quadrant: upper left, upper right, lower right and lower left. Every quadrant must have an image, so with fewer than four images, use some images in more than one quadrant. For example, for a vertical curtain with two images, put one image in both left quadrants and the other in both right quadrants.

With the **diamond** "curtain" option, the quadrants are split along diagonals at 45°, and are in the order upper, right, lower and left.

===== Display modes =====
Use the buttons at the bottom of the window to switch between three modes:

^ Mode ^ What it does ^
| curtain (default) | Shows the images in the four quadrants |
| blink | Shows the quadrants' images one after another, clockwise from the upper left. To change the time between images, edit "seconds" (default 0.5) and press Enter |
| step | Left-click to go to the next image, clockwise; right-click to go back, counterclockwise |

The **History** button shows the command that created the window, so you can see which image is in each quadrant.