Momentum-Apps/firmware-update/process_image.ino

#include "process_image.h"

void process_image(camera_fb_t *frame_buffer)
{
    // Get the camera model reference.
    CameraModel *model = CameraModel::getInstance();

    // If dithering is not disabled, perform dithering on the image. Dithering is the
    // process of approximating the look of a high-resolution grayscale image in a
    // lower resolution by binary values (black & white), thereby representing
    // different shades of gray.
    if (!model->getIsDitheringDisabled())
    {
        dither_image(frame_buffer); // Invokes the dithering process on the frame buffer.
    }

    uint8_t flipper_y = 0;

    // Iterating over specific rows of the frame buffer.
    for (uint8_t y = 28; y < 92; ++y)
    {
        Serial.print("Y:");      // Print "Y:" for every new row.
        Serial.write(flipper_y); // Send the row identifier as a byte.

        // Calculate the actual y index in the frame buffer 1D array by multiplying the
        // y value with the width of the frame buffer. This gives the starting index of
        // the row in the 1D array.
        size_t true_y = y * frame_buffer->width;

        // Iterating over specific columns of each row in the frame buffer.
        for (uint8_t x = 16; x < 144; x += 8)
        { // step by 8 as we're packing 8 pixels per byte.
            uint8_t packed_pixels = 0;
            // Packing 8 pixel values into one byte.
            for (uint8_t bit = 0; bit < 8; ++bit)
            {
                // Check the invert flag and pack the pixels accordingly.
                if (model->getIsInverted())
                {
                    // If invert is true, consider pixel as 1 if it's more than 127.
                    if (frame_buffer->buf[true_y + x + bit] > 127)
                    {
                        packed_pixels |= (1 << (7 - bit));
                    }
                }
                else
                {
                    // If invert is false, consider pixel as 1 if it's less than 127.
                    if (frame_buffer->buf[true_y + x + bit] < 127)
                    {
                        packed_pixels |= (1 << (7 - bit));
                    }
                }
            }
            Serial.write(packed_pixels); // Sending packed pixel byte.
        }

        ++flipper_y;    // Move to the next row.
        Serial.flush(); // Ensure all data in the Serial buffer is sent before moving to the next iteration.
    }
}