Nearest Neighboor on Arduino

[gaouser]

Hi guys I can't really do Nearest Neighboor Resizing on 1D array bitmap with my arduino this is my code

uint16_t* resizePixels(uint16_t *pixels,int w1,int h1,int w2,int h2) {
    uint16_t *temp = new uint16_t[w2*h2] ;
    double x_ratio = w1/(double)w2 ;
    double y_ratio = h1/(double)h2 ;
    double px, py ; 
    for (int i=0;i<h2;i++) {
        for (int j=0;j<w2;j++) {
            px = floor(j*x_ratio) ;
            py = floor(i*y_ratio) ;
            temp[(i*w2)+j] = pixels[(uint16_t)((py*w1)+px)] ;
        }
    }
    return temp ;
}

it seems to do nothing. I use it like this (dbc is drawbitmap function that works)

dBC(x, y, w,h,resizePixels(Bit1,60,30,w,h));

Nothing happened on the screen. but without resize code,it displays so i know dbc function works

[Peter Porter]

I know this thread is two years old. Gaouser's code's main issue is due to the use of floor() and the improper handling of pixel indexing. Below is an updated version for anyone who might have a similar problem:

uint16_t* resizePixels(uint16_t *pixels, int w1, int h1, int w2, int h2) {
    uint16_t *temp = new uint16_t[w2 * h2];
    double x_ratio = (double)w1 / w2;
    double y_ratio = (double)h1 / h2;
    int px, py;  // Use integer for pixel positions

    for (int i = 0; i < h2; i++) {
        for (int j = 0; j < w2; j++) {
            px = (int)(j * x_ratio);  // No need for floor() since casting works here
            py = (int)(i * y_ratio);  // Same here

            // Ensure correct indexing into the original pixel array
            temp[(i * w2) + j] = pixels[(py * w1) + px];
        }
    }
    return temp;
}

[gaouser]

I know this thread is two years old. Gaouser's code's main issue is due to the use of floor() and the improper handling of pixel indexing. Below is an updated version for anyone who might have a similar problem:

uint16_t* resizePixels(uint16_t *pixels, int w1, int h1, int w2, int h2) {
    uint16_t *temp = new uint16_t[w2 * h2];
    double x_ratio = (double)w1 / w2;
    double y_ratio = (double)h1 / h2;
    int px, py;  // Use integer for pixel positions

    for (int i = 0; i < h2; i++) {
        for (int j = 0; j < w2; j++) {
            px = (int)(j * x_ratio);  // No need for floor() since casting works here
            py = (int)(i * y_ratio);  // Same here

            // Ensure correct indexing into the original pixel array
            temp[(i * w2) + j] = pixels[(py * w1) + px];
        }
    }
    return temp;
}

Literally thank you man!

[gaouser]

This forum is really better than Arduino forum. they literally tell you to go resize it on PC there like if the bitmap didnt need to be scaled to 240^240 diffrent combinations