Edge Blending Module

The Edge Blending module makes it easy and affordable to use edge blending in your environment. Edge blending consists of two or three overlapping projected images that have the overlapping regions adjusted to create a seamless blend. Because the outputs of each projector have to overlap in order for blending to occur, the actual width of your output will be smaller than the output resolution.

Before you make your adjustments to the Edge Blending Module, you will need to configure a Matrox DualHead2Go or TripleHead2Go, as well as your computer and ProPresenter, for the proper resolution. Refer to the Matrox Configuration section later in this user guide for details on setting up a Matrox DualHead2Go or TripleHead2Go.

Once you have properly configured your computer and ProPresenter to work with double-wide or triple-wide outputs, you can configure the Blend module. First set the Number of Projectors that you will be using, then set the Screen Ratio height and width. Note that this will be the ratio (size) of your physical screen; if you know the dimensions of your screen you can enter them here, or you can measure your screen with a tape measure and put in the measurements in the Height and Width boxes. Once you have your settings correct, check the Enable Edge Blending box to turn on the feature. Information about your Edge Blend will show in the text box in the middle of the window.

Next you may want to use the blend grid to help you align your projectors and get them as perfectly aligned as possible before adjusting the blend settings. In the View menu select Test Patterns, then select Show Blend Grid. Getting the alignment perfect is critical to being able to achieve the best edge blend possible. If your projectors are slightly out of alignment, your blended area will be more noticeable.

The lower section is used to adjust your blend areas. The black-and-white box is actually the representation of the curve being used to apply the blending adjustments. The three options--Linear, Cubic, and Quadratic--will result in slightly different blends. Test each option to see which works best for you since this varies depending on projectors and environmental factors.

The four sliders allow you to adjust the values of the blend. You will need to spend some time working with these to get the best blend you can. It’s recommended that you start with the first two sliders, Blend and Intensity, at 100% to help you establish a good baseline for adjusting your blend. Gamma adjusts the brightness of the non-blended are compared to the blended regions. If you find that your blended areas are brighter than the rest of your screen, you will want to adjust this settings. Black Level adjusts the video black brightness. Since a projector doesn’t display black, the brightness between the blended area and the rest of the screen may vary slightly.

Due to the wide range of projects and their quality, achieving a “perfect” edge blend is quite difficult, even for the most skilled person. Due to many factors, such as quality of the projectors, age of the lamps in the projectors, number of hours each projector has been used, and even the brand of the lamps in the projector, you may still see a slightly visible area where the images overlap. This occurs with any edge blending solution.