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commit 6e9cd74e810dcc1868754aae0979a13c73a7702d Author: raiden00pl <[email protected]> AuthorDate: Tue Oct 24 13:06:26 2023 +0200 Documentaion: migrate tools/readme --- Documentation/applications/index.rst | 1 + Documentation/applications/tools/index.rst | 33 ++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/Documentation/applications/index.rst b/Documentation/applications/index.rst index 2a7a06d267..926844e753 100644 --- a/Documentation/applications/index.rst +++ b/Documentation/applications/index.rst @@ -34,6 +34,7 @@ more information at the repository. sdr/index.rst system/index.rst testing/index.rst + tools/index.rst wireless/index.rst examples/index.rst diff --git a/Documentation/applications/tools/index.rst b/Documentation/applications/tools/index.rst new file mode 100644 index 0000000000..1504ed7be7 --- /dev/null +++ b/Documentation/applications/tools/index.rst @@ -0,0 +1,33 @@ +=============== +Host Side Tools +=============== + +NxWidgets ``bitmap_converter.py`` +--------------------------------- + +This script converts from any image type supported by Python imaging library to +the RLE-encoded format used by NxWidgets. + +RLE (Run Length Encoding) is a very simply encoding that compress quite well +with certain kinds of images: Images that that have many pixels of the same +color adjacent on a row (like simple graphics). It does not work well with +photographic images. + +But even simple graphics may not encode compactly if, for example, they have +been resized. Resizing an image can create hundreds of unique colors that may +differ by only a bit or two in the RGB representation. This "color smear" is the +result of pixel interpolation (and might be eliminated if your graphics software +supports resizing via pixel replication instead of interpolation). + +When a simple graphics image does not encode well, the symptom is that the +resulting RLE data structures are quite large. The palette structure, in +particular, may have hundreds of colors in it. There is a way to fix the graphic +image in this case. Here is what I do (in fact, I do this on all images prior to +conversion just to be certain): + +- Open the original image in GIMP. +- Select the option to select the number of colors in the image. +- Pick the smallest number of colors that will represent the image faithfully. + For most simple graphic images this might be as few as 6 or 8 colors. +- Save the image as PNG or other lossless format (NOT jpeg). +- Then generate the image.
