node-red-nodes/utility/annotate-image/annotate.html

<script type="text/x-red" data-template-name="annotate-image">
    <div class="form-row">
        <label for="node-input-name"><i class="fa fa-tag"></i> Name</label>
        <input type="text" id="node-input-name" placeholder="Name">
    </div>
    <div id="node-input-row-stroke" class="form-row">
        <label for="node-input-stroke">Stroke</label>
    </div>
    <div class="form-row">
        <label for="node-input-lineWidth">Line Width</label>
        <input type="text" id="node-input-lineWidth">
    </div>
    <div class="form-row">
        <label for="node-input-fontSize">Font Size</label>
        <input type="text" id="node-input-fontSize">
    </div>
    <div id="node-input-row-fontColor" class="form-row">
        <label for="node-input-fontColor">Font Color</label>
    </div>
</script>

<script type="text/x-red" data-help-name="annotate-image">
    <p>A node that can annotate JPEG images with simple shapes and labels.</p>
    <h3>Inputs</h3>
    <dl class="message-properties">
        <dt>payload<span class="property-type">Buffer</span></dt>
        <dd>A Buffer containing a JPEG image. Support for PNG will come soon.</dd>
        <dt>annotations<span class="property-type">Array</span></dt>
        <dd>An array of annotations to apply to the image. See below for details
            of the annotation format.</dd>
    </dl>
    <h3>Outputs</h3>
    <dl class="message-properties">
        <dt>payload<span class="property-type">Buffer</span></dt>
        <dd>The image with any annotations applied.</dd>
    </dl>
    <h3>Details</h3>
    <p>The annotations provided in <code>msg.annotations</code> are applied in order.
       Each annotation is an object with the following properties:</p>
        <dl class="message-properties">
            <dt>type<span class="property-type">string</span></dt>
            <dd><ul>
                <li><code>"rect"</code> - draws a rectangle</li>
                <li><code>"circle"</code> - draws a circle</li>
            </dd>
            <dt>x,y <span class="property-type">number</span></dt>
            <dd>The top-left corner of a <code>rect</code> annotation, or the center of a <code>circle</code> annotation.</dd>
            <dt>w,h <span class="property-type">number</span></dt>
            <dd>The width and height of a <code>rect</code> annotation.</dd>
            <dt>r <span class="property-type">number</span></dt>
            <dd>The radius of a <code>circle</code> annotation.</dd>
            <dt>bbox <span class="property-type">array</span></dt>
            <dd>This can be used instead of <code>x</code>,<code>y</code>,<code>w</code>,<code>h</code> and <code>r</code>. It should
                be an array of four values giving the bounding box of the annotation: <code>[x, y, w, h]</code>.</dd>
            <dt>label <span class="property-type">string</span></dt>
            <dd>An optional piece of text to label the annotation with</dd>
            <dt>stroke <span class="property-type">string</span></dt>
            <dd>Set the color of the annotation. Default: <code>"#ffC000"</code></dd>
            <dt>lineWidth <span class="property-type">number</span></dt>
            <dd>The stroke width used to draw the annotation. Default: <code>5</code></dd>
            <dt>fontSize <span class="property-type">number</span></dt>
            <dd>The font size to use for the label. Default: <code>24</code></dd>
            <dt>fontColor <span class="property-type">string</span></dt>
            <dd>The color of the font to use for the label. Default: <code>"#ffC000"</code></dd>
        </dl>
    <h3>Examples</h3>
    <pre> msg.annotations = [ {
    type: "rect",
    x: 10, y: 10, w: 50, h: 50,
    label: "hello"
}]</pre>
<pre> msg.annotations = [ {
    type: "circle",
    x: 50, y: 50, r: 20
}]</pre>
<pre> msg.annotations = [ {
    type: "rect",
    bbox: [ 10, 10, 50, 50]
}]</pre>
</script>

<script type="text/javascript">

(function() {
    // Lifted from @node-red/editor-client/.../group.js
    // Need to make this a default built-in palette so we don't have to copy
    // it around.
    var colorPalette = [
        "#ff0000",
        "#ffC000",
        "#ffff00",
        "#92d04f",
        "#0070c0",
        "#001f60",
        "#6f2fa0",
        "#000000",
        "#777777"
    ]
    var colorSteps = 3;
    var colorCount = colorPalette.length;
    for (var i=0,len=colorPalette.length*colorSteps;i<len;i++) {
        var ci = i%colorCount;
        var j = Math.floor(i/colorCount)+1;
        var c = colorPalette[ci];
        var r = parseInt(c.substring(1, 3), 16);
        var g = parseInt(c.substring(3, 5), 16);
        var b = parseInt(c.substring(5, 7), 16);
        var dr = (255-r)/(colorSteps+((ci===colorCount-1) ?0:1));
        var dg = (255-g)/(colorSteps+((ci===colorCount-1) ?0:1));
        var db = (255-b)/(colorSteps+((ci===colorCount-1) ?0:1));
        r = Math.min(255,Math.floor(r+j*dr));
        g = Math.min(255,Math.floor(g+j*dg));
        b = Math.min(255,Math.floor(b+j*db));
        var s = ((r<<16) + (g<<8) + b).toString(16);
        colorPalette.push('#'+'000000'.slice(0, 6-s.length)+s);
    }




    RED.nodes.registerType('annotate-image',{
        category: 'utility',
        color:"#f1c2f0",
        defaults: {
            name: {value:""},
            fill: {value:""},
            stroke: {value:"#ffC000"},
            lineWidth: {value:5},
            fontSize: {value: 24},
            fontColor: {value: "#ffC000"}

        },
        inputs:1,
        outputs:1,
        icon: "font-awesome/fa-object-group",
        label: function() {
            return this.name||"Annotate Image";
        },
        labelStyle: function() {
            return this.name?"node_label_italic":"";
        },
        oneditprepare: function() {
            RED.colorPicker.create({
                id:"node-input-stroke",
                value: this.stroke || "#ffC000",
                palette: colorPalette,
                cellPerRow: colorCount,
                cellWidth: 16,
                cellHeight: 16,
                cellMargin: 3
            }).appendTo("#node-input-row-stroke");
            RED.colorPicker.create({
                id:"node-input-fontColor",
                value: this.fontColor || "#ffC000",
                palette: colorPalette,
                cellPerRow: colorCount,
                cellWidth: 16,
                cellHeight: 16,
                cellMargin: 3
            }).appendTo("#node-input-row-fontColor");
        }
    });
})();
</script>