Getting access violation writing location 0xCDCDCDCD when trying to make an image bigger on pixel level in C

I'm trying to make an image 4 times its size by making a temp image, with double the original images width and height.Then take information from each pixel on the original image and give it to 4 pixels on the temp image. Something like this.

Original image:

[1] [2]

[3] [4]

To temp image:

[1][1] [2][2]

[3][3] [4][4]

But I get an access violation writing location 0xCDCDCDCD. Here is my function code:

void makeBigger(Image* plain)
{
Image temp;

temp.height = plain->height * 2;
temp.width = plain->width * 2;

temp.pixels = (Pixel**)malloc(sizeof(Pixel*) * temp.height);
for (int i = 0, k = 0; i < temp.height; i+2, k++)
{
    temp.pixels[i] = (Pixel*)malloc(sizeof(Pixel) * temp.width);
    for (int j = 0, g = 0; j < temp.width; j+2, g++)
    {
        temp.pixels[i][j].r = plain->pixels[k][g].r;
        temp.pixels[i][j+1].r = plain->pixels[k][g].r;
        temp.pixels[i+1][j].r = plain->pixels[k][g].r;
        temp.pixels[i+1][j+1].r = plain->pixels[k][g].r;

        temp.pixels[i][j].g = plain->pixels[k][g].g;
        temp.pixels[i][j+1].g = plain->pixels[k][g].g;
        temp.pixels[i+1][j].g = plain->pixels[k][g].g;
        temp.pixels[i+1][j+1].g = plain->pixels[k][g].g;

        temp.pixels[i][j].b = plain->pixels[k][g].b;
        temp.pixels[i][j+1].b = plain->pixels[k][g].b;
        temp.pixels[i+1][j].b = plain->pixels[k][g].b;
        temp.pixels[i+1][j+1].b = plain->pixels[k][g].b;
    }
}

*plain = temp;

}

On the violation seems to occur on the line

temp.pixels[i+1][j].r = plain->pixels[k][g].r;

as that is when the program breaks and the error shows. What is causing this violation and why? What can be done to fix this?

Solution

Inside the outer loop, at every iteration:

You initialize temp.pixels[i] to point to a properly allocated memory block
You attempt to write into the memory block pointed by temp.pixels[i]
You attempt to write into the memory block pointed by temp.pixels[i+1]

But since you do not initialize temp.pixels[i+1] to point to a properly allocated memory block, attempting to access memory with this variable leads to a memory access violation (or more generally, undefined behavior).