Java, LibGDX - Gaussian Blur Color Separator Trouble - Receiving Negative Value

I have been working on a gaussian blur on java and libgdx. It mostly works...

This is the image that I am trying to blur.

This is the result.

The problem is the red value equals -1 in most cases rather than something like 255. I have searched lots of forums and they don't address this problem. I have also noticed that most people use ARGB8888 but badlogics library's doesn't have the ARGB8888 format it has RGBA8888 format. I also searched websites for how the RGBA8888 stores its information in bits and I some what understand, but not enough to fix the problem.

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.PixmapIO;
import com.badlogic.gdx.utils.BufferUtils;
import com.badlogic.gdx.utils.ScreenUtils;

import java.awt.image.ConvolveOp;
import java.nio.ByteBuffer;


public class ScreenCapture {
    public void capture(){
        float output = 0;

        int[] all = new int[11];

        Pixmap originalPixmap = new Pixmap(Gdx.files.internal("graphics/menu/test.png"));

        Pixmap pixmapVertical = new Pixmap(originalPixmap.getWidth(), originalPixmap.getHeight(), Pixmap.Format.RGBA8888);
        Pixmap pixmap = new Pixmap(pixmapVertical.getWidth(), pixmapVertical.getHeight(), Pixmap.Format.RGBA8888);

        for (int y = 0;y < originalPixmap.getHeight();y++){
            for (int x = 0;x < originalPixmap.getWidth();x++){
                for (int i = -5; i < 5; i++) {
                    all[i+5] = originalPixmap.getPixel(x+i, y);
                }
                pixmapVertical.setColor(blur(all));
                pixmapVertical.drawPixel(x, y);
            }
        }
        for (int x = 0;x < pixmapVertical.getWidth();x++){
            for (int y = 0;y < pixmapVertical.getHeight();y++){

                for (int i = -5; i < 5; i++) {
                    all[i+5] = pixmapVertical.getPixel(x, y+i);
                }
                pixmap.setColor(blur(all));
                pixmap.drawPixel(x, y);
            }
        }


        PixmapIO.writePNG(Gdx.files.local("screen.png"), pixmap);
        originalPixmap.dispose();
        pixmapVertical.dispose();
        pixmap.dispose();

        int rgb = 0xffffffff;
        int test = ((rgb & 0xff000000) >> 24);
        System.out.println(test);

    }
    private int blur(int[] all){
        float[] weight = {0.0093f, 0.028002f, 0.065984f, 0.121703f, 0.175713f, 0.198596f, 0.175713f, 0.121703f, 0.065984f, 0.028002f, 0.0093f};
        float r = 0;
        float g = 0;
        float b = 0;
        float a = 0;
        for (int i = 0; i < 11; i++){
            b +=  ( ((all[i] & 0x0000ff00)>>8)*weight[i]);
            r +=  ( ( (all[i] & 0xff000000)>>24 )*weight[i]);
            g +=  ( ((all[i] & 0x00ff0000)>>16)*weight[i]);
            a +=  ( ((all[i] & 0x000000ff))*weight[i]);
        }
        return (((int) r << 24 | (int)g << 16 | (int)b << 8 | (int)a ));
    }
}

The far left value will cause you number to be negative. eg. When red is 255 your number is negative. You can avoid this by &'ing with 255.

int r += ( ( (all[i]>>24) & 0xff) )*weight[i]);

Essentially -1&0xff = 255

There is also the unsigned right shift operator >>> which would give you the same results.

int r += ( (all[i]>>>24) )*weight[i]);