Hi there,
im having a hard time figuring out how to convert images to an array to display them on the 13.3" spectra from seeedstudio. I tried nearly every possible option on image2cpp but the image displayed is complete “garbage”. I can see in the colorful example in arduino that it needs to be RGB565 (16-bit color), but then the provided sample image is const unsigned char, not in the format the image2cpp converter gives me with RGB565 (horizontal - 2 bytes per pixel 565).
I´m really out of ideas here, I searched the forum but couldn’t find ANY topic on color conversion, so it would be great if somebody could point me to the (most probably) simple and obvious solution 
thank you!
Hello,
I spent the entire day troubleshooting the same issue. The documentation in the header file of the example BMP image is incorrect and misleading.
The header states:
- Format: RGB565 (16-bit color)
This is incorrect. The actual encoding is 4 bits per pixel (bpp4), not 16-bit RGB565. Each byte represents two pixels, where each nibble (4 bits) corresponds to one pixel.
Example:
0x22 → first pixel = 0x2 (green), second pixel = 0x2 (green)
Additionally, the color representation is not standard RGB but uses indexed values:
-
0x0 = white
-
0x2 = green
-
0x6 = red
-
0xB = yellow
-
0xD = blue
-
0xF = black
The listed resolution (1200×1600) and the supported color set are correct, but the format description (RGB565, 16-bit) in the example BMP header file is wrong.