boofcv.alg.interpolate.impl.BilinearRectangle_S16 Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of ip Show documentation
BoofCV is an open source Java library for real-time computer vision and robotics applications.
There is a newer version: 0.26
/*
 * Copyright (c) 2011-2013, 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.interpolate.impl;

import boofcv.alg.interpolate.InterpolateRectangle;
import boofcv.struct.image.ImageFloat32;
import boofcv.struct.image.ImageSInt16;


/**
 * 
 * Performs bilinear interpolation to extract values between pixels in an image.
 * Image borders are detected and handled appropriately.
 * 
 *
 * 
 * NOTE: This code was automatically generated using {@link GenerateBilinearRectangle}.
 * 
 *
 * @author Peter Abeles
 */
public class BilinearRectangle_S16 implements InterpolateRectangle {

	private ImageSInt16 orig;

	private short data[];
	private int stride;

	public BilinearRectangle_S16(ImageSInt16 image) {
		setImage(image);
	}

	public BilinearRectangle_S16() {
	}

	@Override
	public void setImage(ImageSInt16 image) {
		this.orig = image;
		this.data = orig.data;
		this.stride = orig.getStride();
	}

	@Override
	public ImageSInt16 getImage() {
		return orig;
	}

	@Override
	public void region(float tl_x, float tl_y, ImageFloat32 output ) {
		if( tl_x < 0 || tl_y < 0 || tl_x + output.width > orig.width || tl_y + output.height > orig.height ) {
			throw new IllegalArgumentException("Region is outside of the image");
		}
		int xt = (int) tl_x;
		int yt = (int) tl_y;
		float ax = tl_x - xt;
		float ay = tl_y - yt;

		float bx = 1.0f - ax;
		float by = 1.0f - ay;

		float a0 = bx * by;
		float a1 = ax * by;
		float a2 = ax * ay;
		float a3 = bx * ay;

		int regWidth = output.width;
		int regHeight = output.height;
		final float results[] = output.data;
		boolean borderRight = false;
		boolean borderBottom = false;

		// make sure it is in bounds or if its right on the image border
		if (xt + regWidth >= orig.width || yt + regHeight >= orig.height) {
			if( (xt + regWidth > orig.width || yt + regHeight > orig.height) )
				throw new IllegalArgumentException("requested region is out of bounds");
			if( xt+regWidth == orig.width ) {
				regWidth--;
				borderRight = true;
			}
			if( yt+regHeight == orig.height ) {
				regHeight--;
				borderBottom = true;
			}
		}

		// perform the interpolation while reducing the number of times the image needs to be accessed
		for (int i = 0; i < regHeight; i++) {
			int index = orig.startIndex + (yt + i) * stride + xt;
			int indexResults = output.startIndex + i*output.stride;

			float XY = data[index];
			float Xy = data[index + stride];

			int indexEnd = index + regWidth;
			// for( int j = 0; j < regWidth; j++, index++ ) {
			for (; index < indexEnd; index++) {
				float xY = data[index + 1];
				float xy = data[index + stride + 1];

				float val = a0 * XY + a1 * xY + a2 * xy + a3 * Xy;

				results[indexResults++] = val;
				XY = xY;
				Xy = xy;
			}
		}
		
		// if touching the image border handle the special case
		if( borderBottom || borderRight )
			handleBorder(output, xt, yt, ax, ay, bx, by, regWidth, regHeight, results, borderRight, borderBottom);
	}

	private void handleBorder( ImageFloat32 output,
							  int xt, int yt,
							  float ax, float ay, float bx, float by,
							  int regWidth, int regHeight, float[] results,
							  boolean borderRight, boolean borderBottom) {

		if( borderRight ) {
			for( int y = 0; y < regHeight; y++ ) {
				int index = orig.startIndex + (yt + y) * stride + xt + regWidth;
				int indexResults = output.startIndex + y*output.stride + regWidth;

				float XY = data[index];
				float Xy = data[index + stride];

				results[indexResults] = by*XY + ay*Xy;
			}

			if( borderBottom ) {
				output.set(regWidth,regHeight, orig.get(xt+ regWidth,yt+regHeight));
			} else {
				float XY = orig.get(xt+ regWidth,yt+regHeight-1);
				float Xy = orig.get(xt+ regWidth,yt+regHeight);

				output.set(regWidth,regHeight-1, by*XY + ay*Xy);
			}
		}
		if( borderBottom ) {
			for( int x = 0; x < regWidth; x++ ) {
				int index = orig.startIndex + (yt + regHeight) * stride + xt + x;
				int indexResults = output.startIndex + regHeight *output.stride + x;

				float XY = data[index];
				float Xy = data[index + 1];

				results[indexResults] = bx*XY + ax*Xy;
			}

			if( !borderRight ) {
				float XY = orig.get(xt+regWidth-1,yt+ regHeight);
				float Xy = orig.get(xt+regWidth, regHeight);

				output.set(regWidth-1, regHeight, by*XY + ay*Xy);
			}
		}
	}
}