RGB565 转 RGB888 的2种实现方式

for (int i = 0; i < image_width * image_height; i++) {
  uint16_t pixel = ((uint16_t *)(fb->buf))[i];
  // for inference
  uint8_t hb = pixel & 0xFF;
  uint8_t lb = pixel >> 8;
  uint8_t r = (lb & 0x1F) << 3;
  uint8_t g = ((hb & 0x07) << 5) | ((lb & 0xE0) >> 3);
  uint8_t b = (hb & 0xF8);
  image_data[3 * i] = r;
  image_data[3 * i + 1] = g;
  image_data[3 * i + 2] = b;
}

更为适配能力强的方案为

fmt2rgb888(fb->buf, fb->len, fb->format, image_data)