/**
* Returns the kernel for finding the X derivative.
*
* @param type Type of gradient
* @param isInteger integer or floating point kernels
* @return The kernel. Can be 1D or 2D
*/
public static KernelBase lookupKernelX(DerivativeType type, boolean isInteger) {
switch (type) {
case PREWITT:
return GradientPrewitt.getKernelX(isInteger);
case SOBEL:
return GradientSobel.getKernelX(isInteger);
case THREE:
return GradientThree.getKernelX(isInteger);
case TWO_0:
return GradientTwo0.getKernelX(isInteger);
case TWO_1:
return GradientTwo1.getKernelX(isInteger);
}
throw new IllegalArgumentException("Unknown kernel type: " + type);
}
/**
* Computes the gradient using the specified image type.
*
* @param type Type of gradient to compute
* @param input Input image
* @param derivX Output. Derivative X
* @param derivY Output. Derivative Y
* @param borderType How it should handle borders. null == skip border
* @param <I> Input image type
* @param <D> Output image type
*/
public static <I extends ImageSingleBand, D extends ImageSingleBand> void gradient(
DerivativeType type, I input, D derivX, D derivY, BorderType borderType) {
ImageBorder<I> border =
BorderType.SKIP == borderType ? null : FactoryImageBorder.general(input, borderType);
switch (type) {
case PREWITT:
if (input instanceof ImageFloat32) {
GradientPrewitt.process(
(ImageFloat32) input,
(ImageFloat32) derivX,
(ImageFloat32) derivY,
(ImageBorder_F32) border);
} else if (input instanceof ImageUInt8) {
GradientPrewitt.process(
(ImageUInt8) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else if (input instanceof ImageSInt16) {
GradientPrewitt.process(
(ImageSInt16) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else {
throw new IllegalArgumentException(
"Unknown input image type: " + input.getClass().getSimpleName());
}
break;
case SOBEL:
if (input instanceof ImageFloat32) {
GradientSobel.process(
(ImageFloat32) input,
(ImageFloat32) derivX,
(ImageFloat32) derivY,
(ImageBorder_F32) border);
} else if (input instanceof ImageUInt8) {
GradientSobel.process(
(ImageUInt8) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else if (input instanceof ImageSInt16) {
GradientSobel.process(
(ImageSInt16) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else {
throw new IllegalArgumentException(
"Unknown input image type: " + input.getClass().getSimpleName());
}
break;
case THREE:
if (input instanceof ImageFloat32) {
GradientThree.process(
(ImageFloat32) input,
(ImageFloat32) derivX,
(ImageFloat32) derivY,
(ImageBorder_F32) border);
} else if (input instanceof ImageUInt8) {
GradientThree.process(
(ImageUInt8) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else if (input instanceof ImageSInt16) {
GradientThree.process(
(ImageSInt16) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else {
throw new IllegalArgumentException(
"Unknown input image type: " + input.getClass().getSimpleName());
}
break;
case TWO_0:
if (input instanceof ImageFloat32) {
GradientTwo0.process(
(ImageFloat32) input,
(ImageFloat32) derivX,
(ImageFloat32) derivY,
(ImageBorder_F32) border);
} else if (input instanceof ImageUInt8) {
GradientTwo0.process(
(ImageUInt8) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else if (input instanceof ImageSInt16) {
GradientTwo0.process(
(ImageSInt16) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else {
throw new IllegalArgumentException(
"Unknown input image type: " + input.getClass().getSimpleName());
}
break;
case TWO_1:
if (input instanceof ImageFloat32) {
GradientTwo1.process(
(ImageFloat32) input,
(ImageFloat32) derivX,
(ImageFloat32) derivY,
(ImageBorder_F32) border);
} else if (input instanceof ImageUInt8) {
GradientTwo1.process(
(ImageUInt8) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else if (input instanceof ImageSInt16) {
GradientTwo1.process(
(ImageSInt16) input,
(ImageSInt16) derivX,
(ImageSInt16) derivY,
(ImageBorder_I32) border);
} else {
throw new IllegalArgumentException(
"Unknown input image type: " + input.getClass().getSimpleName());
}
break;
default:
throw new IllegalArgumentException("Unknown type: " + type);
}
}