Sfoglia il codice sorgente

Rewrite README, include util's, remove duplicate palette

tags/v1.8.0
Xerbo 4 anni fa
parent
commit
58a71f4ade
8 ha cambiato i file con 87 aggiunte e 113 eliminazioni
  1. +2
    -1
      .gitignore
  2. +74
    -101
      README.md
  3. +11
    -11
      main.c
  4. +0
    -0
      palettes/Falsecolor-N19-June-High-Veg.png
  5. BIN
      palettes/N19-June-High-Vegetation.png
  6. BIN
      util/PrecipitationPalette.png
  7. BIN
      util/TempPalette.png
  8. BIN
      util/Temperature.png

+ 2
- 1
.gitignore Vedi File

@@ -43,7 +43,8 @@
# Program specifics
*.png
!textlogo.png
!palettes/*
!palettes/*.png
!util/*.png
*.wav
aptdec



+ 74
- 101
README.md Vedi File

@@ -2,126 +2,97 @@

Copyright (c) 2004-2009 Thierry Leconte (F4DWV), Xerbo (xerbo@protonmail.com) 2019-2020

## Description
## Introduction

Aptdec is an FOSS program that decodes images transmitted by NOAA weather satellites. These satellites transmit continuously (among other things), medium resolution (1px/4km) images of the earth on 137 MHz.
These transmissions could be easily received with an simple antenna and cheap SDR. Then the transmission can easily be decoded in narrow band FM mode.
Aptdec is a FOSS program that decodes images transmitted by NOAA weather satellites. These satellites transmit constantly (among other things) medium resolution (4km/px) images of the earth over a analog mode called APT.
These transmissions can easily be received with a cheap SDR and simple antenna. Then the transmission can be decoded in narrow FM mode.

Aptdec can convert these audio files into `png` images.
Aptdec can turn the audio recordings into PNG images and generate images such as:

For each audio file up to 6 images can be generated:
- Raw image: both channels with full telemetry included
- Individual channel: one of the channels form the image
- Temperature image: a temperature compensated image derived from the IR channel
- Palleted image: a image where the color is derived from a palette (false color, etc)
- MCIR: a false color that uses a underlay map for color

1. Raw image: contains the 2 transmitted channel images + telemetry and synchronization pulses.
2. Calibrated channel A image
3. Calibrated channel B image
4. Temperature compensated IR image
5. Palleted image
6. MCIR (Map Color InfraRed) image
The input audio format can be anything supported by `libsndfile` (although only tested with WAV and FLAC). Sample rate doesn't matter, although lower samples rates will process faster.

The input audio file must be mono with a sample rate in the range of 4160-62400 Hz, lower samples rates will process faster.
Aptdec uses `libsndfile` to read the input audio, so any format supported by `libsndfile` may be used (however it has only tested with `.wav` files).

## Compilation

Aptdec is portable since it is written in standard C.
It has successfully compiled and ran on Debian with both `gcc`, `clang` and `tcc` and will most likely work on any Unix platform.
Just edit the Makefile and run `make` (no configure script as of right now).

Aptdec uses `libsndfile`, `libpng` and `libm`.
The `snd.h` and `png.h` headers must be present on your system.
If they are not on standard path, edit the include path in the Makefile.

## Usage

To compile
`make`

To run without installing
`./aptdec [options] audio files...`

To install
`sudo make install`

To run once installed
`aptdec [options] audio files...`

To uninstall
`sudo make uninstall`

## Options
## Quick start

```sh
sudo apt install git gcc libsndfile-dev libpng-dev
git clone https://github.com/Xerbo/aptdec.git && cd aptdec
make
```
-i [r|a|b|t|m|p]
Output image type
Raw (r), Channel A (a), Channel B (b), Palleted (p), Temperature (t) or MCIR (m)
Default: "ab"

-d <dir>
Images destination directory (optional)
Default: Current directory

-s [15|16|17|18|19]
Satellite number
For temperature calibration
Default: "19"

-e [r|a|b|c|t|m]
Effects
Histogram equalise (h), Crop Telemetry (t), Denoise (d), Precipitation (p) or Linear equalise (l)
Defaults: off

-m <file>
Map file generated by wxmap

-o <filename>
Output image filename

-p <filename>
Path to palette
## Examples

-r
Realtime decode. When decoding in realtime it is highly recommended to choose a plain raw image.
To create an image from `gqrx_20200527_115730_137914960.wav` (output filename will be `gqrx_20200527_115730_137914960-r.png`)
```sh
./aptdec gqrx_20200527_115730_137914960.wav
```

## Output

Generated images are outputted in PNG and are 24 bit RGB for all image types apart from pure greyscale images.
To manually set the output filename
```sh
./aptdec -o image.png gqrx_20200527_115730_137914960.wav
```

Image names are `audiofile-x.png`, where `x` is:
Decode all WAV files in the current directory and put them in `images`
```sh
./aptdec -d images *.wav
```

- `r` for raw images
- `a` channel A images
- `b` channel B images
- `p` for a paletted image
- `t` for temperature calibrated images
- `m` for MCIR images
Apply a denoise filter (see [Post-Processing Effects](#post-processing-effects) for a full list of post-processing effects)
```sh
./aptdec -e d gqrx_20200527_115730_137914960.wav
```

Currently there are 6 available effects:
Create a temperature compensated image for NOAA 18
```sh
./aptdec -i t -s 18 gqrx_20200527_115730_137914960.wav
```

- `t` for crop telemetry, off by default, only has effects on raw images
- `h` for histogram equalise
- `d` for a median denoise filter
- `p` for a precipitation overlay
- `f` to flip the image (for southbound passes)
- `l` to linearly equalise the image, stretch the colors in the image to black and white
Apply a falsecolor palette
```sh
./aptdec -i p -p palettes/WXtoImg-N18-HVC.png gqrx_20200527_115730_137914960.wav
```

## Examples
## Usage

`aptdec -d images -i ab *.wav`
### Arguments

This will process all `.wav` files in the current directory, generate calibrated channel A and B images and put them in the `images` directory.
```
-i [r|a|b|t|m|p] Output type (kinda stackable)
-e [t|h|l|d|p|f] Effects (stackable)
-o <path> Output filename
-d <path> Destination directory
-s (15-19) Satellite number
-m <path> Path to WXtoImg map
-p <path> Path to palette
-r Realtime decode
```

`aptdec -e dh -i b audio.wav`
### Image types

Decode `audio.wav` with denoise and histogram equalization and save it into the current directory.
- `r`: Raw Image
- `a`: Channel A
- `b`: Channel B
- `t`: Temperature
- `m`: MCIR (Map Color InfraRed)
- `p`: Palleted

`aptdec -e d -p palettes/N19-June-High-Vegetation.png -i p audio.wav`
### Post-Processing Effects

Create a false color image from the `N19-June-High-Vegetation.png` palette.
- `t`: Crop telemetry (only effects raw image)
- `h`: Histogram equalise
- `l`: Linear equalise
- `d`: Denoise
- `p`: Precipitation overlay
- `f`: Flip image (for southbound passes)

## Realtime decoding

As of recently a realtime output was added allowing realtime decoding of images.
Aptdec even supports decoding in realtime. The following decodes the audio coming from the audio device `pulseaudio alsa_output.pci-0000_00_1b.0.analog-stereo`

```
mkfifo /tmp/aptaudio
@@ -129,17 +100,19 @@ aptdec /tmp/aptaudio
sox -t pulseaudio alsa_output.pci-0000_00_1b.0.analog-stereo.monitor -c 1 -t wav /tmp/aptaudio
```

Perform a realtime decode with the audio being played out of `alsa_output.pci-0000_00_1b.0.analog`. To stop the decode kill the `sox` process.
To stop the decode and calibrate the image simply kill the `sox` process.

## Palette formatting

Palettes are PNG images that are 256x256 in size with 24bit RGB color. The X axis is the value of Channel A and the Y axis is the value of Channel B
Palettes are just simple PNG images, 256x256px in size with 24bit RGB color. The X axis represents the value of Channel A and the Y axis the value of Channel B.

## Further Reading

## Further reading
[User's Guide for Building and Operating
Environmental Satellite Receiving Stations](https://noaasis.noaa.gov/NOAASIS/pubs/Users_Guide-Building_Receive_Stations_March_2009.pdf)

[https://noaasis.noaa.gov/NOAASIS/pubs/Users_Guide-Building_Receive_Stations_March_2009.pdf](https://noaasis.noaa.gov/NOAASIS/pubs/Users_Guide-Building_Receive_Stations_March_2009.pdf)
[https://web.archive.org/web/20141220021557/https://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/tables.htm](https://web.archive.org/web/20141220021557/https://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/tables.htm)
[NOAA KLM coefficients](https://web.archive.org/web/20141220021557/https://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/tables.htm)

## License

See LICENSE.
See `LICENSE`

+ 11
- 11
main.c Vedi File

@@ -315,6 +315,13 @@ static void usage(void) {
fprintf(stderr,
"Aptdec [options] audio files ...\n"
"Options:\n"
" -i [r|a|b|t|m|p] Output image\n"
" r: Raw\n"
" a: Channel A\n"
" b: Channel B\n"
" t: Temperature\n"
" m: MCIR\n"
" p: Paletted image\n"
" -e [t|h|d|p|f|l] Effects\n"
" t: Crop telemetry\n"
" h: Histogram equalise\n"
@@ -322,19 +329,12 @@ static void usage(void) {
" p: Precipitation\n"
" f: Flip image\n"
" l: Linear equalise\n"
" -i [r|a|b|c|t|m|p] Output image\n"
" r: Raw\n"
" a: Channel A\n"
" b: Channel B\n"
" t: Temperature\n"
" m: MCIR\n"
" p: Paletted image\n"
" -d <dir> Image destination directory.\n"
" -o <name> Output filename\n"
" -o <path> Output filename\n"
" -d <path> Image destination directory.\n"
" -s [15-19] Satellite number\n"
" -m <file> Map file\n"
" -m <path> Map file\n"
" -p <path> Path to palette\n"
" -r Realtime decode\n"
" -p Path to palette\n"
"\nRefer to the README for more infomation\n");

exit(EINVAL);


palettes/N19-FC-June-High-Vegetation.png → palettes/Falsecolor-N19-June-High-Veg.png Vedi File


BIN
palettes/N19-June-High-Vegetation.png Vedi File

Prima Dopo
Larghezza: 256  |  Altezza: 256  |  Dimensione: 71 KiB

BIN
util/PrecipitationPalette.png Vedi File

Prima Dopo
Larghezza: 1  |  Altezza: 58  |  Dimensione: 1.4 KiB

BIN
util/TempPalette.png Vedi File

Prima Dopo
Larghezza: 1  |  Altezza: 256  |  Dimensione: 901 B

BIN
util/Temperature.png Vedi File

Prima Dopo
Larghezza: 298  |  Altezza: 68  |  Dimensione: 2.0 KiB

Caricamento…
Annulla
Salva