Algorithm to rotate an image 90 degrees in place? (No extra memory)

Question

In an embedded C app, I have a large image that I\'d like to rotate by 90 degrees. Currently I use the well-known simple algorithm to do this. However, this algorithm requi

Answer 1

Not sure what processing you will do after the rotation, but you can leave it alone and use another function to read rotated pixel from the original memory.

uint16_t getPixel90(Image *img, int x, int y) 
{
    return img->data[(img->height - x) * img->width + y];
}

Where input parameter x and y has swapped dimension from original