Add description of the new icon-converter (pp_png2hpp.py).

Splash-and-other-images.md

@@ -1,3 +1,5 @@
+
+# Splash screen
 For converting back and forth between the image and source you can use `xxd`. In a Windows environment you can use this command in the Linux Subsystem installing one of the versions available (i.e. [Ubuntu](https://ubuntu.com/tutorials/tutorial-ubuntu-on-windows#1-overview)). 
 
 ### From .bmp to .hpp
@@ -6,15 +8,59 @@ For converting back and forth between the image and source you can use `xxd`. In
 ### From .hpp to .bmp
 `xxd -r -p input.hpp output_image.bmp `
 
+## Python converter for Splash Screen
+
+There is also a python helper in [firmware/tools/bmp_tools](https://github.com/portapack-mayhem/mayhem-firmware/tree/next/firmware/tools/bmp_tools/) 
+
 # Firmware icons
 
-There is a special file that contains all the firmware icons `firmware\application\bitmap.hpp` but this file should not be edited directly, instead, new icons should be created in `firmware\graphics` and then run `firmware\tools\make_bitmap.py <DIRECTORY>` to create `bitmap.hpp`.
+The special file `firmware/application/bitmap.hpp` contains all firmware icons.  
+This file should not be edited directly! Instead, new icons should be copied in [firmware/graphics](https://github.com/portapack-mayhem/mayhem-firmware/tree/next/firmware/graphics) and then run `python [firmware/tools/bitmap_tools/pp_png2hpp.py](https://github.com/portapack-mayhem/mayhem-firmware/blob/next/firmware/tools/bitmap_tools/pp_png2hpp.py) <DIRECTORY> bitmap.hpp` to create `bitmap.hpp`.
 
 For operating that Python3 script, `Pillow` library is required: `pip install pillow`
 
-From bash, the command that creates and moves the bitmap file is:
+## make_bitmap.py - Convert a folder contains one or more icon.png to one bitmap.hpp
+The `make_bitmap.py` is the traditional helper, well tested. The folder with the icons is given as argument and generates the `bitmap.hpp`. This file needs to be copied to `mayhem-firmware/firmware/application/`. Starting from the `tools/ folder, the command is:  
+```
+python3 bitmap_tools/make_bitmap.py ../graphics/ && mv bitmap.hpp ../application/bitmap.hpp
+```
 
-`python3 make_bitmap.py ../graphics/ && mv bitmap.hpp ../application/bitmap.hpp`
+The icon size needs to be a multiple of 8. The generated icon is black/white.  
+
+## bitmap_arr_reverse_decode.py - Convert bitmap array to icon.png
+The `bitmap_arr_reverse_decode.py` takes an array from the bitmap.hpp and convert it back to a png.  
+
+
+## pp_png2hpp.py - Convert both ways
+The `pp_png2hpp.py` is based on the previous scripts, as all in one solution.  
+
+With the `--hpp bitmap.hpp` file and the `--graphics /folder_to/png_icons/` arguments, this script will generate a `bitmap.hpp`.  
+Add the `--reverse` argument to generate png icons from a given `bitmap.hpp`.  
+
+The reverse function got a parser, for automatic get the filename and size of the image.
+
+#### Example
+From the `tools/` folder:
+```
+$ ./bitmap_tools/pp_png2hpp.py ../application/bitmap.hpp ../graphics
+Converting from png to hpp
+From path ../graphics/ to file ../application/bitmap.hpp
+Find your bitmap.hpp at ../application/bitmap.hpp
+```
+
+To reverse the icons from the .hpp to png icons use the parameter `--reverse`. Default is only the mayhem logo, named `titlebar_image`:
+```
+$ ./bitmap_tools/pp_png2hpp.py ../application/bitmap.hpp /home/lupus/work/hackrf/tmp/ --reverse 
+Reverse: Converting from hpp to png
+Converting icon titlebar_image
+```
+
+Add the parameter `--icon <icon name>` to convert another icon or `all` to convert all available icons at once:  
+```
+$ ./bitmap_tools/pp_png2hpp.py ../application/bitmap.hpp /home/lupus/work/hackrf/tmp/ --reverse --icon all
+```
+
+**Note**: It is not a recovery, the icons will be new generated. The new icons are black/white, even if the original icons where transparent.  
 
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