Android : Java Android - Change canvas resolution to make pixelated effect

So i have a canvas, that is the resolution of my device's screen, but i want to make a pixelated effect... Kinda like what is happening in the game: Eliss Infinity.

I have tried to make an int[][] and then draw the colors with a 'for' loop in my render method, but that makes my pretty high end device(Oneplus One) slow down to 20 - 30 fps instead of 60.

This is what i've done:

package com.ccxi11.protecter;

import android.graphics.Canvas;
import android.graphics.Paint;

public class PixelHandler {

private float widthScale, heightScale;
private int width, height;
private int[][] colors;

public PixelHandler(int width, int height) {

    widthScale = Display.getScreenWidth() / width;
    heightScale = Display.getScreenHeight() / height;

    this.width = width;
    this.height = height;

    colors = new int[width][height];

}

public void render(Canvas c, Paint p) {

    for(int x = 0; x < width; x++) {
        for(int y = 0; y < height; y++) {
            p.setColor(colors[x][y]);
            c.drawRect(x * widthScale, y * heightScale, x * widthScale + widthScale, y * heightScale + heightScale, p);
        }
    }

}

public void setColor(int x, int y, int color) {
    colors[x][y] = color;
}
public int getColor(int x, int y) {
    return colors[x][y];
}

}

Is there a way where i can draw the individual pixels without everything being laggy?

-Rasmus