ImageFilter.java

package com.flounder.fishDiary.image;

import android.graphics.Bitmap;

public class ImageFilter {

    private ImageData image = null;
    private double mSize = 0.5;

    public ImageFilter(Bitmap bitmap) {
        image = new ImageData(bitmap);
    }

    public ImageData processImage() {
        int width = image.getWidth();
        int height = image.getHeight();
        int ratio = width > height ? height * 32768 / width : width * 32768 / height;

        int cx = width >> 1;
        int cy = height >> 1;
        int max = cx * cx + cy * cy;
        int min = (int) (max * (1 - mSize));
        int diff = max - min;

        int R, G, B;
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                R = image.getRComponent(x, y);
                G = image.getGComponent(x, y);
                B = image.getBComponent(x, y);

                // Calculate distance to center and adapt aspect ratio
                int dx = cx - x;
                int dy = cy - y;
                if (width > height) {
                    dx = (dx * ratio) >> 15;
                } else {
                    dy = (dy * ratio) >> 15;
                }
                int distSq = dx * dx + dy * dy;
                float v = ((float) distSq / diff) * 255;
                R = (int) (R + (v));
                G = (int) (G + (v));
                B = (int) (B + (v));
                R = (R > 255 ? 255 : (R < 0 ? 0 : R));
                G = (G > 255 ? 255 : (G < 0 ? 0 : G));
                B = (B > 255 ? 255 : (B < 0 ? 0 : B));
                image.setPixelColor(x, y, R, G, B);
            }
        }
        return image;
    }
}