// Catalano Imaging Library
// The Catalano Framework
//
// Copyright © Diego Catalano, 2012-2016
// diego.catalano at live.com
//
// Copyright © Andrew Kirillov, 2007-2008
// andrew.kirillov at gmail.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//
package Catalano.Imaging.Tools;
import Catalano.Imaging.FastBitmap;
/**
* Gather statistics about image in Gray or RGB color space.
* @author Diego Catalano
*/
public class ImageStatistics {
private ImageHistogram gray;
private ImageHistogram red;
private ImageHistogram green;
private ImageHistogram blue;
private int pixels;
/**
* Image histogram of gray channel.
* @return Histogram.
*/
public ImageHistogram getHistogramGray(){
if (gray == null)
throw new IllegalArgumentException("Histogram gray is null");
return gray;
}
/**
* Image histogram of red channel.
* @return Histogram.
*/
public ImageHistogram getHistogramRed() {
if (red == null)
throw new IllegalArgumentException("Histogram red is null");
return red;
}
/**
* Image histogram of green channel.
* @return Histogram.
*/
public ImageHistogram getHistogramGreen() {
if (green == null)
throw new IllegalArgumentException("Histogram green is null");
return green;
}
/**
* Image histogram of blue channel.
* @return Histogram.
*/
public ImageHistogram getHistogramBlue() {
if (blue == null)
throw new IllegalArgumentException("Histogram blue is null");
return blue;
}
/**
* Initialize a new instance of the ImageStatistics class.
* @param fastBitmap Image to be processed.
*/
public ImageStatistics(FastBitmap fastBitmap) {
this(fastBitmap, 256);
}
/**
* Initialize a new instance of the ImageStatistics class.
* @param fastBitmap Image to be processed.
* @param bins Number of bins.
*/
public ImageStatistics(FastBitmap fastBitmap, int bins){
pixels = 0;
red = green = blue = gray = null;
int size = fastBitmap.getWidth() * fastBitmap.getHeight();
if (fastBitmap.isGrayscale()) {
int[] g = new int[bins];
int G;
for (int i = 0; i < size; i++) {
G = fastBitmap.getGray(i);
g[G * bins / 256]++;
pixels++;
}
gray = new ImageHistogram(g);
}
else if (fastBitmap.isRGB()){
int[] r = new int[bins];
int[] g = new int[bins];
int[] b = new int[bins];
int R,G,B;
for (int i = 0; i < size; i++) {
R = fastBitmap.getRed(i);
G = fastBitmap.getGreen(i);
B = fastBitmap.getBlue(i);
r[R * bins / 256]++;
g[G * bins / 256]++;
b[B * bins / 256]++;
pixels++;
}
red = new ImageHistogram(r);
green = new ImageHistogram(g);
blue = new ImageHistogram(b);
}
}
/**
* Count pixels.
* @return amount of pixels.
*/
public int PixelsCount() {
return pixels;
}
/**
* Calculate Mean value.
* @param fastBitmap Image to be processed.
* @return Mean.
*/
public static float Mean(FastBitmap fastBitmap){
return Mean(fastBitmap, 0, 0, fastBitmap.getWidth(), fastBitmap.getHeight());
}
/**
* Calculate Mean value.
* @param fastBitmap Image to be processed.
* @param startX Initial X axis coordinate.
* @param startY Initial Y axis coordinate.
* @param width Width.
* @param height Height.
* @return Mean.
*/
public static float Mean(FastBitmap fastBitmap, int startX, int startY, int width, int height){
float mean = 0;
if (fastBitmap.isGrayscale()){
for (int i = startX; i < height; i++) {
for (int j = startY; j < width; j++) {
mean += fastBitmap.getGray(i, j);
}
}
return mean / (width * height);
}
else{
throw new IllegalArgumentException("ImageStatistics: Only compute mean in grayscale images.");
}
}
/**
* Calculate Variance.
* @param fastBitmap Image to be processed.
* @return Variance.
*/
public static float Variance(FastBitmap fastBitmap){
float mean = Mean(fastBitmap);
return Variance(fastBitmap, mean);
}
/**
* Calculate Variance.
* @param fastBitmap Image to be processed.
* @param mean Mean.
* @return Variance.
*/
public static float Variance(FastBitmap fastBitmap, float mean){
return Variance(fastBitmap, mean, 0, 0, fastBitmap.getWidth(), fastBitmap.getHeight());
}
/**
* Calculate Variance.
* @param fastBitmap Image to be processed.
* @param mean Mean.
* @param startX Initial X axis coordinate.
* @param startY Initial Y axis coordinate.
* @param width Width.
* @param height Height.
* @return Variance.
*/
public static float Variance(FastBitmap fastBitmap, float mean, int startX, int startY, int width, int height){
float sum = 0;
if (fastBitmap.isGrayscale()){
for (int i = startX; i < height; i++) {
for (int j = startY; j < width; j++) {
sum += Math.pow(fastBitmap.getGray(i, j) - mean, 2);
}
}
return sum / (float)((width * height) - 1);
}
else{
throw new IllegalArgumentException("ImageStatistics: Only compute variance in grayscale images.");
}
}
/**
* Get maximum gray value in the image.
* @param fastBitmap Image to be processed.
* @return Maximum gray.
*/
public static int Maximum (FastBitmap fastBitmap){
return Maximum(fastBitmap, 0, 0, fastBitmap.getWidth(), fastBitmap.getHeight());
}
/**
* Get maximum gray value in the image.
* @param fastBitmap Image to be processed.
* @param startX Initial X axis coordinate.
* @param startY Initial Y axis coordinate.
* @param width Width.
* @param height Height.
* @return Maximum gray.
*/
public static int Maximum(FastBitmap fastBitmap, int startX, int startY, int width, int height){
int max = 0;
for (int i = startX; i < height; i++) {
for (int j = startY; j < width; j++) {
int gray = fastBitmap.getGray(i, j);
if (gray > max) {
max = gray;
}
}
}
return max;
}
/**
* Get minimum gray value in the image.
* @param fastBitmap Image to be processed.
* @return minimum gray.
*/
public static int Minimum (FastBitmap fastBitmap){
return Minimum(fastBitmap, 0, 0, fastBitmap.getWidth(), fastBitmap.getHeight());
}
/**
* Get minimum gray value in the image.
* @param fastBitmap Image to be processed.
* @param startX Initial X axis coordinate.
* @param startY Initial Y axis coordinate.
* @param width Width.
* @param height Height.
* @return Minimum gray.
*/
public static int Minimum(FastBitmap fastBitmap, int startX, int startY, int width, int height){
int min = 255;
for (int i = startX; i < height; i++) {
for (int j = startY; j < width; j++) {
int gray = fastBitmap.getGray(i, j);
if (gray < min) {
min = gray;
}
}
}
return min;
}
}
Ads help maintain this website.