LiveDemo_Images_HTMLHelper_v28.cshtml

    <!-- Create TextControl and load document -->
    <div class="tx-container">
        @Html.TXTextControl().TextControl(settings =>
        {
            settings.Dock = DockStyle.Fill;
        }).LoadText(Server.MapPath("~/App_Data/Documents/editing_images.tx"),
            StreamType.InternalUnicodeFormat).Render()
    </div>

...

    <!-- Input for a local image -->
    <input type="file" ... accept=".gif,.png,.jpg,.jpeg,.bmp,*" onchange="LoadLocalImage(this.files)">