mirror of https://github.com/SixLabors/ImageSharp
James South
12 years ago
5 changed files with 277 additions and 51 deletions
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// --------------------------------------------------------------------------------------------------------------------
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// <copyright file="YCbCrColor.cs" company="James South">
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// Copyright (c) James South.
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// Licensed under the Apache License, Version 2.0.
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// </copyright>
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// <summary>
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// Represents an YCbCr (luminance, chroma, chroma) color used in digital imaging systems.
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// <see href="http://en.wikipedia.org/wiki/YCbCr" />
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// </summary>
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// --------------------------------------------------------------------------------------------------------------------
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namespace ImageProcessor.Imaging.Colors |
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{ |
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using System; |
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using System.Drawing; |
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using ImageProcessor.Common.Extensions; |
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/// <summary>
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/// Represents an YCbCr (luminance, chroma, chroma) color used in digital imaging systems.
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/// <see href="http://en.wikipedia.org/wiki/YCbCr"/>
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/// </summary>
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public struct YCbCrColor |
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{ |
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/// <summary>
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/// Represents a <see cref="YCbCrColor"/> that is null.
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/// </summary>
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public static readonly YCbCrColor Empty = new YCbCrColor(); |
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/// <summary>
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/// The y luminance component.
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/// </summary>
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private readonly float y; |
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/// <summary>
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/// The u chroma component.
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/// </summary>
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private readonly float cb; |
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/// <summary>
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/// The v chroma component.
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/// </summary>
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private readonly float cr; |
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/// <summary>
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/// Initializes a new instance of the <see cref="YCbCrColor"/> struct.
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/// </summary>
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/// <param name="y">The y luminance component.</param>
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/// <param name="cb">The u chroma component.</param>
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/// <param name="cr">The v chroma component.</param>
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private YCbCrColor(float y, float cb, float cr) |
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{ |
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this.y = y; //Math.Max(0.0f, Math.Min(1.0f, y));
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this.cb = cb; //Math.Max(-0.5f, Math.Min(0.5f, cb));
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this.cr = cr; //Math.Max(-0.5f, Math.Min(0.5f, cr));
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} |
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/// <summary>
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/// Gets the Y luminance component.
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/// </summary>
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public float Y |
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{ |
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get |
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{ |
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return this.y; |
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} |
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} |
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/// <summary>
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/// Gets the U chroma component.
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/// </summary>
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public float Cb |
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{ |
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get |
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{ |
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return this.y; |
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} |
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} |
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/// <summary>
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/// Gets the V chroma component.
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/// </summary>
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public float Cr |
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{ |
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get |
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{ |
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return this.y; |
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} |
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} |
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/// <summary>
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/// Creates a <see cref="YCbCrColor"/> structure from the three 32-bit YCbCr
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/// components (luminance, chroma, and chroma) values.
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/// </summary>
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/// <param name="y">The y luminance component.</param>
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/// <param name="cb">The u chroma component.</param>
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/// <param name="cr">The v chroma component.</param>
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/// <returns>
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/// The <see cref="YCbCrColor"/>.
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/// </returns>
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public static YCbCrColor FromYCbCr(float y, float cb, float cr) |
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{ |
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return new YCbCrColor(y, cb, cr); |
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} |
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/// <summary>
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/// Creates a <see cref="YCbCrColor"/> structure from the specified <see cref="System.Drawing.Color"/> structure
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/// </summary>
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/// <param name="color">
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/// The <see cref="System.Drawing.Color"/> from which to create the new <see cref="YCbCrColor"/>.
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/// </param>
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/// <returns>
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/// The <see cref="YCbCrColor"/>.
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/// </returns>
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public static YCbCrColor FromColor(Color color) |
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{ |
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float r = color.R; |
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float g = color.G; |
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float b = color.B; |
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float y = (float)((0.299 * r) + (0.587 * g) + (0.114 * b)); |
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float cb = 128 - (float)((-0.168736 * r) - (0.331264 * g) + (0.5 * b)); |
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float cr = 128 + (float)((0.5 * r) - (0.418688 * g) - (0.081312 * b)); |
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return new YCbCrColor(y, cb, cr); |
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} |
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/// <summary>
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/// Allows the implicit conversion of an instance of <see cref="System.Drawing.Color"/> to a
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/// <see cref="YCbCrColor"/>.
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/// </summary>
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/// <param name="color">
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/// The instance of <see cref="System.Drawing.Color"/> to convert.
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/// </param>
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/// <returns>
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/// An instance of <see cref="YCbCrColor"/>.
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/// </returns>
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public static implicit operator YCbCrColor(Color color) |
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{ |
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return FromColor(color); |
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} |
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/// <summary>
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/// Allows the implicit conversion of an instance of <see cref="YCbCrColor"/> to a
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/// <see cref="System.Drawing.Color"/>.
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/// </summary>
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/// <param name="ycbcr">
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/// The instance of <see cref="YCbCrColor"/> to convert.
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/// </param>
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/// <returns>
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/// An instance of <see cref="System.Drawing.Color"/>.
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/// </returns>
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public static implicit operator Color(YCbCrColor ycbcr) |
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{ |
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byte r = Convert.ToInt32(ycbcr.Y + (1.402 * (ycbcr.Cr - 128))).ToByte(); |
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byte g = Convert.ToInt32(ycbcr.Y - (0.34414 * (ycbcr.Cb - 128)) - (0.71414 * (ycbcr.Cr - 128))).ToByte(); |
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byte b = Convert.ToInt32(ycbcr.Y + (1.772 * (ycbcr.Cb - 128))).ToByte(); |
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return Color.FromArgb(255, r, g, b); |
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} |
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} |
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} |
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