boofcv.alg.filter.derivative.GradientTwo1 Maven / Gradle / Ivy
/*
* 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.filter.derivative;
import boofcv.alg.InputSanityCheck;
import boofcv.alg.filter.derivative.impl.GradientTwo1_Standard;
import boofcv.core.image.border.ImageBorder_F32;
import boofcv.core.image.border.ImageBorder_S32;
import boofcv.struct.convolve.Kernel1D;
import boofcv.struct.convolve.Kernel1D_F32;
import boofcv.struct.convolve.Kernel1D_I32;
import boofcv.struct.image.GrayF32;
import boofcv.struct.image.GrayS16;
import boofcv.struct.image.GrayU8;
/**
*
* Computes the image's first derivative along the x and y axises using [-1 1] kernel, where the "center" of the
* kernel is on the 1.
*
*
* The 1-D kernel allows the image's gradient to be computed efficiently but is more sensitive to local noise.
*
*
* For example in an integer image:
* derivX(x,y) = img(x,y) - img(x-1,y)
* derivY(x,y) = img(x,y) - img(x,y-1)
*
*
* @author Peter Abeles
*/
public class GradientTwo1 {
public static Kernel1D_I32 kernelDeriv_I32 = new Kernel1D_I32(new int[]{-1,1}, 2, 1);
public static Kernel1D_F32 kernelDeriv_F32 = new Kernel1D_F32(new float[]{-1,1}, 2, 1);
/**
* Returns the kernel for computing the derivative along the x-axis.
*/
public static Kernel1D getKernelX( boolean isInteger ) {
if( isInteger )
return kernelDeriv_I32;
else
return kernelDeriv_F32;
}
/**
* Computes the derivative of an {@link GrayU8} along the x and y axes.
*
* @param orig Which which is to be differentiated. Not Modified.
* @param derivX Derivative along the x-axis. Modified.
* @param derivY Derivative along the y-axis. Modified.
* @param border Specifies how the image border is handled. If null the border is not processed.
*/
public static void process(GrayU8 orig,
GrayS16 derivX, GrayS16 derivY, ImageBorder_S32 border ) {
InputSanityCheck.checkSameShape(orig, derivX, derivY);
GradientTwo1_Standard.process(orig, derivX, derivY);
if( border != null ) {
DerivativeHelperFunctions.processBorderHorizontal(orig, derivX , kernelDeriv_I32, border);
DerivativeHelperFunctions.processBorderVertical(orig, derivY , kernelDeriv_I32, border);
}
}
/**
* Computes the derivative of an {@link GrayS16} along the x and y axes.
*
* @param orig Which which is to be differentiated. Not Modified.
* @param derivX Derivative along the x-axis. Modified.
* @param derivY Derivative along the y-axis. Modified.
* @param border Specifies how the image border is handled. If null the border is not processed.
*/
public static void process(GrayS16 orig,
GrayS16 derivX, GrayS16 derivY, ImageBorder_S32 border) {
InputSanityCheck.checkSameShape(orig, derivX, derivY);
GradientTwo1_Standard.process(orig, derivX, derivY);
if( border != null ) {
DerivativeHelperFunctions.processBorderHorizontal(orig, derivX , kernelDeriv_I32, border);
DerivativeHelperFunctions.processBorderVertical(orig, derivY , kernelDeriv_I32, border);
}
}
/**
* Computes the derivative of an {@link GrayF32} along the x and y axes.
*
* @param orig Which which is to be differentiated. Not Modified.
* @param derivX Derivative along the x-axis. Modified.
* @param derivY Derivative along the y-axis. Modified.
* @param border Specifies how the image border is handled. If null the border is not processed.
*/
public static void process(GrayF32 orig,
GrayF32 derivX, GrayF32 derivY, ImageBorder_F32 border) {
InputSanityCheck.checkSameShape(orig, derivX, derivY);
GradientTwo1_Standard.process(orig, derivX, derivY);
if( border != null ) {
DerivativeHelperFunctions.processBorderHorizontal(orig, derivX , kernelDeriv_F32, border);
DerivativeHelperFunctions.processBorderVertical(orig, derivY , kernelDeriv_F32, border);
}
}
}