ZEN NDI Graduated Background Generator

ReadMe File

1) General features & FAQs for all ZEN NDI utilities


2) The basic functionality is in generating a 4-way gradient-filled image using selectable colours for the four corners of the rectangle, although pairs can be set to the same value in order to acheive a simple 2-way gradient. The gradient image can either remain static or the colours can rotate in a clockwise (CW) or anticlockwise (CCW) direction. A slider control adjusts the period between colour changes (i.e. faster rotational speed as the slider moves to the right).

3) The gradient image can either fill the screen, be horizontally (H-Split) or vertically mirrored (V_Split) as two half-size rectangles, or be mirrored both horizontally and vertically (in Quad mode) using quarter-size rectangles.

4) The Cloud overlay option adds a fixed fractal noise pattern self-keyed over the background. There’s a choice of patterns and the overlay can be scrolled up or down via the vertical speed control slider

5) A mask image can be loaded to control the transparency of the composite colour-gradient-plus-clouds image, based the the luma values of the mask. It can be in .bmp, .gif, .jpg, .png or .tif format, colour or greyscale. In the default mode, high luma values are opaque, low luma values are transparent. “Invert Trans” reverses this. If the loaded image is a 32bit image with its own Alpha/Transparency, then “Use Mask Alpha” allows this data to be used in place of the “normal” image data. “Reveal Alpha” will show a preview of this image data if present.

6) The Video preview option (on by default) enables a continuous video preview in the user interface. When disabled the preview will only update momentarily when the main pattern generation settings are changed. This will save some CPU usage, although not as much as disabling the Cloud overlay.

7) Resolution is currently limited to 1920×1080, but due to the nature of the image it won’t suffer much if scaling up is required in the host app.

8) Multiple versions can be run on the same PC, with the NDI ident names being sequentially auto-numbered.

9) There are five Presets which hold different configurations (colours, patterns, etc). The Paste button will copy the last used preset to the current one (e.g. to copy number 3 to number 5, select 3 then select 5 and click on Paste)

10) On exit, a “last.gbg” file will be created with the current group of five presets, plus it’s possible to save a “default.gbg” file from the main drop-down menu in the title bar. If the default file exists, it will be loaded on startup. Click the “Load last” button to load the last used preset group. NOTE: Preset files do not include the settings for the new features added in v1.0.1.5

Some examples of how the background generator can work – including alpha masks

Martin Kay
ZEN Computer Services


v1.0.0.1 5-Mar-2017 First public release. Limited to 1920×1080 or lower resolutions.

v1.0.0.2 7-Mar-2017 Added five preset memories and basic load/save of defaults and last-used preset configurations.

v1.0.0.3 14-Mar-2017 Some optimisations to reduce CPU usage at lower colour rotation speeds. Watermark removed after several minutes of use.

v1.0.0.4 12-Sep-2017 Recompiled to extend the expiry date. No other changes.

v1.0.1.5 3-Dec-2017 New features included user-loaded alpha mask plus cloud scrolling.

v1.0.1.6 21-May-2018 Recompiled to extend the expiry date. No new features.

v1.0.1.7 22-Nov-2018 Recompiled to extend the expiry date. NDI output only includes Alpha information when the “Use Mask” box is ticked.

v1.0.1.8 26-Dec-2018 Recompiled to use the included NDI v3.8 DLL. No new features.

v1.0.1.9 1-Sep-2019 Recompiled to extend the expiry date whilst waiting for the NDI 4.0 release

v1.0.2.10 2-Feb-2020 Recompiled to extend the expiry date and use the NDI 4.15 DLL. Both 32 bit (x86) and 64 bit (x64) code versions are included.

v1.0.2.11 27-Sep-2020 Recompiled to extend the expiry date and use the NDI 4.53 DLL.

v1.0.3.12 18-Mar-2021 Recompiled to extend expiry date and use the NDI v4.62 DLL. Also added F1 & system menu methods of accessing the ReadMe online, and sponsor ads at start-up.

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