DetectEdgesExtensions.cs

// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.

using SixLabors.ImageSharp.Processing.Processors.Convolution;

namespace SixLabors.ImageSharp.Processing
{
    /// <summary>
    /// Defines edge detection extensions applicable on an <see cref="Image"/> using Mutate/Clone.
    /// </summary>
    public static class DetectEdgesExtensions
    {
        /// <summary>
        /// Detects any edges within the image.
        /// Uses the <see cref="KnownEdgeDetectorKernels.Sobel"/> kernel operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(this IImageProcessingContext source) =>
            DetectEdges(source, KnownEdgeDetectorKernels.Sobel);

        /// <summary>
        /// Detects any edges within the image.
        /// Uses the <see cref="KnownEdgeDetectorKernels.Sobel"/> kernel operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            Rectangle rectangle) =>
            DetectEdges(source, KnownEdgeDetectorKernels.Sobel, rectangle);

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The 2D edge detector kernel.</param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetector2DKernel kernel) =>
            DetectEdges(source, kernel, true);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetector2DKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The 2D edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetector2DKernel kernel,
            bool grayscale)
        {
            var processor = new EdgeDetector2DProcessor(kernel, grayscale);
            source.ApplyProcessor(processor);
            return source;
        }

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The 2D edge detector kernel.</param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetector2DKernel kernel,
            Rectangle rectangle) =>
            DetectEdges(source, kernel, true, rectangle);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetector2DKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The 2D edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetector2DKernel kernel,
            bool grayscale,
            Rectangle rectangle)
        {
            var processor = new EdgeDetector2DProcessor(kernel, grayscale);
            source.ApplyProcessor(processor, rectangle);
            return source;
        }

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The edge detector kernel.</param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorKernel kernel) =>
            DetectEdges(source, kernel, true);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetectorKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorKernel kernel,
            bool grayscale)
        {
            var processor = new EdgeDetectorProcessor(kernel, grayscale);
            source.ApplyProcessor(processor);
            return source;
        }

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The edge detector kernel.</param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorKernel kernel,
            Rectangle rectangle) =>
            DetectEdges(source, kernel, true, rectangle);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetectorKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">The edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorKernel kernel,
            bool grayscale,
            Rectangle rectangle)
        {
            var processor = new EdgeDetectorProcessor(kernel, grayscale);
            source.ApplyProcessor(processor, rectangle);
            return source;
        }

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">Thecompass edge detector kernel.</param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorCompassKernel kernel) =>
            DetectEdges(source, kernel, true);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetectorCompassKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">Thecompass edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorCompassKernel kernel,
            bool grayscale)
        {
            var processor = new EdgeDetectorCompassProcessor(kernel, grayscale);
            source.ApplyProcessor(processor);
            return source;
        }

        /// <summary>
        /// Detects any edges within the image operating in grayscale mode.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">Thecompass edge detector kernel.</param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorCompassKernel kernel,
            Rectangle rectangle) =>
            DetectEdges(source, kernel, true, rectangle);

        /// <summary>
        /// Detects any edges within the image using a <see cref="EdgeDetectorCompassKernel"/>.
        /// </summary>
        /// <param name="source">The image this method extends.</param>
        /// <param name="kernel">Thecompass edge detector kernel.</param>
        /// <param name="grayscale">
        /// Whether to convert the image to grayscale before performing edge detection.
        /// </param>
        /// <param name="rectangle">
        /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to alter.
        /// </param>
        /// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
        public static IImageProcessingContext DetectEdges(
            this IImageProcessingContext source,
            EdgeDetectorCompassKernel kernel,
            bool grayscale,
            Rectangle rectangle)
        {
            var processor = new EdgeDetectorCompassProcessor(kernel, grayscale);
            source.ApplyProcessor(processor, rectangle);
            return source;
        }
    }
}