Image Processor Blog Post

JordanRobinson.TintProcessor.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <mediaLibrary>
      <requestProtection>
        <protectedMediaQueryParameters>
          <parameter description="tint" name="tint"/>
        </protectedMediaQueryParameters>
        <customMediaQueryParameters>
          <parameter description="tint" name="tint"/>
        </customMediaQueryParameters>
      </requestProtection>
      <requestParser type="Sitecore.Resources.Media.MediaRequest, Sitecore.Kernel">
        <patch:attribute name="type">JordanRobinson.Requests.TintMediaRequest, JordanRobinson.Processors</patch:attribute>
      </requestParser>
    </mediaLibrary>
    <pipelines>
      <getMediaStream>
        <processor type="JordanRobinson.Processors.TintProcessor, JordanRobinson.Processors"
                   patch:before="processor[@type='Sitecore.Resources.Media.ThumbnailProcessor, Sitecore.Kernel']"/>
      </getMediaStream>
    </pipelines>
  </sitecore>
</configuration>

TintMediaRequest.cs

using System.Web;
using Sitecore.Configuration;
using Sitecore.Diagnostics;
using Sitecore.Resources.Media;

namespace JordanRobinson.Requests
{
    public class TintMediaRequest : MediaRequest
    {
        private HttpRequest _innerRequest;
        private MediaUrlOptions _mediaQueryString;
        private MediaUri _mediaUri;
        private MediaOptions _options;

        public override MediaRequest Clone()
        {
            return new TintMediaRequest
                       {
                           _innerRequest = _innerRequest,
                           _mediaUri = _mediaUri,
                           _options = _options,
                           _mediaQueryString = _mediaQueryString
                       };
        }

        protected override MediaOptions GetOptions()
        {
            var queryString = InnerRequest.QueryString;

            if (!string.IsNullOrEmpty(queryString.Get("tint")))
            {
                _options = new MediaOptions();

                ProcessCustomParameters(_options);

                if (!_options.CustomOptions.ContainsKey("tint") && !string.IsNullOrEmpty(queryString.Get("tint")))
                {
                    _options.CustomOptions.Add("tint", queryString.Get("tint"));
                }
            }
            else
            {
                var mediaQueryString = GetMediaQueryString();
                _options = new MediaOptions
                {
                    AllowStretch = mediaQueryString.AllowStretch,
                    BackgroundColor = mediaQueryString.BackgroundColor,
                    IgnoreAspectRatio = mediaQueryString.IgnoreAspectRatio,
                    Scale = mediaQueryString.Scale,
                    Width = mediaQueryString.Width,
                    Height = mediaQueryString.Height,
                    MaxWidth = mediaQueryString.MaxWidth,
                    MaxHeight = mediaQueryString.MaxHeight,
                    Thumbnail = mediaQueryString.Thumbnail
                };

                if (mediaQueryString.DisableMediaCache)
                {
                    _options.UseMediaCache = false;
                }

                var keys = queryString.AllKeys;
                for (var i = 0; i < keys.Length; i = i + 1)
                {
                    var value = keys[i];

                    if (value != null && queryString.Get(value) != null)
                    {
                        _options.CustomOptions[value] = queryString.Get(value);
                    }
                }
            }

            if (!IsRawUrlSafe)
            {
                if (Settings.Media.RequestProtection.LoggingEnabled)
                {
                    var urlReferrer = GetUrlReferrer();
                    Log.SingleError($"MediaRequestProtection: An invalid/missing hash value was encountered. The expected hash value: {HashingUtils.GetAssetUrlHash(this.InnerRequest.Path)}. Media URL: { InnerRequest.Path }, Referring URL: { (string.IsNullOrEmpty(urlReferrer) ? "(empty)" : urlReferrer)}", this);
                }

                _options = new MediaOptions();
            }

            return _options;
        }
    }
}

TintProcessor.cs

using System;
using System.Drawing;
using System.IO;
using System.Linq;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Resources.Media;

namespace JordanRobinson.Processors
{
    public class TintProcessor
    {
        private static readonly string[] ImageExtensions = { "bmp", "jpeg", "jpg", "png", "gif" };

        public void Process(GetMediaStreamPipelineArgs args)
        {
            Assert.ArgumentNotNull(args, nameof(args));

            var outputStream = args.OutputStream;
            if (outputStream == null)
            {
                return;
            }

            if (!ImageExtensions.Any(i => i.Equals(args.MediaData.Extension, StringComparison.InvariantCultureIgnoreCase)))
            {
                return;
            }

            var tint = args.Options.CustomOptions["tint"];

            if (!string.IsNullOrEmpty(tint))
            {
                var color = ColorTranslator.FromHtml(tint);

                var outputMedia = Stream.Synchronized(GetTintedImage(color, outputStream.MediaItem));
                args.OutputStream = new MediaStream(outputMedia, args.MediaData.Extension, outputStream.MediaItem);
            }
        }

        private Stream GetTintedImage(Color color, MediaItem mediaItem)
        {
            var outputStream = new MemoryStream();
            var mediaStream = mediaItem.GetMediaStream();
            var image = Image.FromStream(mediaStream);
            var proc = new ImageProcessor.ImageFactory();
            proc.Load(image);

            proc = proc.Tint(color);
            proc.Save(outputStream);

            return outputStream;
        }
    }
}