/*
 * Copyright (c) 2011-2016, Peter Abeles. All Rights Reserved.
 *
 * This file is part of BoofCV (http://boofcv.org).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package boofcv.alg.feature.describe.impl;

import boofcv.alg.misc.GImageMiscOps;
import boofcv.struct.feature.NccFeature;
import boofcv.struct.image.GrayU8;
import boofcv.testing.BoofTesting;
import org.junit.Test;

import java.util.Random;

import static org.junit.Assert.*;

/**
 * @author Peter Abeles
 */
public class TestImplDescribePointPixelRegionNCC_U8 {

	Random rand = new Random(234);

	GrayU8 img = new GrayU8(20,30);

	public TestImplDescribePointPixelRegionNCC_U8() {
		GImageMiscOps.fillUniform(img, rand, 0, 30);
	}

	@Test
	public void inner() {
		BoofTesting.checkSubImage(this, "checkInner", false, img, 4, 6, 7, 5);
		BoofTesting.checkSubImage(this, "checkInner", false, img, 7,3,4,5);
		BoofTesting.checkSubImage(this, "checkInner", false, img, 4,6,2,4);
	}

	public void checkInner(GrayU8 image , int c_x , int c_y , int w , int h ) {
		ImplDescribePointPixelRegionNCC_U8 alg = new ImplDescribePointPixelRegionNCC_U8(w,h);

		NccFeature desc = new NccFeature(alg.getDescriptorLength());
		alg.setImage(image);
		assertTrue(alg.isInBounds(c_x, c_y));
		alg.process(c_x, c_y, desc);

		int y0 = c_y-h/2;
		int x0 = c_x-w/2;
		double mean = 0;
		for( int y = y0; y < y0+h; y++ ) {
			for( int x = x0; x < x0+w; x++ ) {
				mean += image.get(x,y);
			}
		}
		mean /= w*h;
		double variance = 0;
		for( int y = y0; y < y0+h; y++ ) {
			for( int x = x0; x < x0+w; x++ ) {
				double a = image.get(x,y) - mean;
				variance += a*a;
			}
		}
		variance /= w*h;
		assertEquals(desc.mean,mean,1e-8);
		assertEquals(desc.sigma,Math.sqrt(variance),1e-8);

		int index = 0;
		for( int y = y0; y < y0+h; y++ ) {
			for( int x = x0; x < x0+w; x++ , index++ ) {
				assertEquals(image.get(x,y)-mean,desc.value[index],1e-4);
			}
		}
	}

	@Test
	public void border() {
		BoofTesting.checkSubImage(this, "checkBorder", false, img, 0,0,5,7);
		BoofTesting.checkSubImage(this, "checkBorder", false, img, img.width-1,img.height-1,5,7);
		BoofTesting.checkSubImage(this, "checkBorder", false, img, 100,200,5,7);
	}

	public void checkBorder(GrayU8 image , int c_x , int c_y , int w , int h ) {
		ImplDescribePointPixelRegionNCC_U8 alg = new ImplDescribePointPixelRegionNCC_U8(w,h);

		NccFeature desc = new NccFeature(alg.getDescriptorLength());
		alg.setImage(image);
		assertFalse(alg.isInBounds(c_x, c_y));
	}
}