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Image Converter/Compressor for Embedded Devices

+ Description

8bbw2c.sh

converts B/W image to 8-bit C/C++ array. Please note, the image should be Black & White, neither Grayscale nor in Color.

16brgb2c.sh

converts 16-bit color binary image into RGB565 C/C++ array.

img2bin.sh

converts images to binary or C/C++ RAW pixel array (RGB565 and RGB888). Tested only for .jpg and .png images for now.

Saving PNGs in Adobe Illustrator:

File - Export As:

  1. File format - PNG
  2. Non-interlaced
  3. Optimization - preferable "None"

Bin header format:

# Name Length in bytes
1 Compression (boolean) 2
2 Width 2
3 Height 2
4 Flag of alpha channel 2
5 Dominant (background) color (2 * Bytes Per Pixel)
6 Color as Alpha channel (2 * Bytes Per Pixel)

INFO:
The above scripts are using in, out and .tmp directories in order to seek for a source and store the final result accordingly.

mix8bbw2c.sh

converts a few similar images into the dependant scructure of binary arrays. The script tries to find an image that has the most similarities with all the others and creates *_base_bmp array. Then converts all the other images to binary, excluding the *_base_bmp block. In principle the logic is diplayed on the image below.

Image Compressor Logic

In order to decode and display the binaries on the device you can use the following functions:

  • drawBmpRGB - displays RGB565 bitmap graphic
  • drawBmpRGBA - drawing an image that has alpha channel or use an alpha color
  • drawBmpBW - drawing single 8-bit B/W compressed bitmap
  • drawBmpBWChunk - drawing 8-bit B/W chunked compressed bitmap

The following is an example of encoded (using mix8bbw2c.sh script) B/W chunked bitmaps:

/**
 * fmt: 8-bit B/W chunked compressed image map
 * img: lcrtc7
 * bmp: lcrtc7_bmp (non-inverted)
 * gen: mix8bbw2c.sh (v.1.3) at 27.07.2020 20:07:25
*/
const uint8_t off_base_bmp[] PROGMEM = {
0xFF,0x02,0x00,0x0C,0xFF,0x03....
};

const chunk8b_t off_chunk PROGMEM = {
    off_base_bmp,
    0,
    16, 16, 0
};

const uint8_t alert_chunk_bmp[] PROGMEM = {
0x00,0x37,0x00,0x02,0x00,0x02...
};

const chunk8b_t alert_chunk PROGMEM = {
    off_base_bmp,
    alert_chunk_bmp,
    16, 16, 30
};

const uint8_t working_chunk_bmp[] PROGMEM = {
0x00,0x31,0x00,0x01,0xFF,0x01...
};

const chunk8b_t working_chunk PROGMEM = {
    off_base_bmp,
    working_chunk_bmp,
    16, 16, 108
};
bugtracker
 Please refer to issues 🪲 if you have any suggestion or found an error.