This is a JOSM paint style for entering the diameter of trees based on measurements taken from aerial imagery. At lower zoom levels trees are drawn as solid green dots if they have a value in the 'crown_diameter' tag, or yellow if they do not. At higher zoom levels, trees with crown_diameter's entered are shown as open circles with a diameter scaled based on the entered value.

This paint style is useful, either for visualizing existing data and checking that the data is correct, and it is also useful for entering new crown diameters by easily showing trees which currently lack that measurement. This style was used in the method of measuring described in this ​diary entry.

meta
{
        title: "Tree-Crown_Diameter";
        description: "This style shows which trees have a tree crown diameter entered on them and if so, attempts to show the trees relative to their size.";
        author: "AndrewBuck";
        version: "1.0.5_2019-04-21";
        link: "https://josm.openstreetmap.de/wiki/Styles/TreeCrownDiameter";
}

/* General things. */
canvas
{
        fill-color: #000;
        default-lines: true;
        default-points: true;
}

way::*
{
        width: 2;
        major-z-index: 3.0;
        linejoin: miter;
        linecap: none;
}

area:closed
{
        fill-opacity: 0.5;
}

*::*
{
        text-halo-color: white;
        text-anchor-horizontal: center;
        text-anchor-vertical: center;
}

node[natural=tree][!diameter_crown]
{
        symbol-shape: circle;

        symbol-fill-color: yellow;
        symbol-stroke-color: black;

        symbol-size: 6;
        symbol-stroke-width: 1.5;
}

node[natural=tree][diameter_crown]
{
        symbol-shape: circle;
        symbol-stroke-color: lime;
}

node|z21[natural=tree][diameter_crown] { symbol-size: eval(20.0 * tag("diameter_crown")); }
node|z20[natural=tree][diameter_crown] { symbol-size: eval(10.0 * tag("diameter_crown")); }
node|z19[natural=tree][diameter_crown] { symbol-size: eval(5.0 * tag("diameter_crown")); }
node|z18[natural=tree][diameter_crown] { symbol-size: eval(2.5 * tag("diameter_crown")); }
node|z17[natural=tree][diameter_crown] { symbol-size: eval(1.25 * tag("diameter_crown")); }
node|z16[natural=tree][diameter_crown] { symbol-size: eval(0.625 * tag("diameter_crown")); }

node|z-15[natural=tree][diameter_crown]
{
        symbol-fill-color: green;
        symbol-stroke-color: black;
        symbol-size: 6;
        symbol-stroke-width: 1.5;
}

area[landuse=forest], area[natural=wood]
{
        fill-color: lime;
        stroke-color: green;
}

way[barrier=hedge]
{
        width: 4.0;
        color: green;
}

Styles_TreeCrownDiameter-style.mapcss, Styles_TreeCrownDiameter.zip