When I load an image into the icon property of a marker it displays with its original size, which is a lot bigger than it should be.

I want to resize to the standard to a smaller size. What is the best way to do this?

Code:

function addMyPos(latitude,longitude){
  position = new google.maps.LatLng(latitude,longitude)
  marker = new google.maps.Marker({
    position: position,
    map: map,
    icon: "../res/sit_marron.png"
  });
}

Solution 1:

If the original size is 100 x 100 and you want to scale it to 50 x 50, use scaledSize instead of Size.

var icon = {
    url: "../res/sit_marron.png", // url
    scaledSize: new google.maps.Size(50, 50), // scaled size
    origin: new google.maps.Point(0,0), // origin
    anchor: new google.maps.Point(0, 0) // anchor
};

var marker = new google.maps.Marker({
    position: new google.maps.LatLng(lat, lng),
    map: map,
    icon: icon
});

Solution 2:

As mentionned in comments, this is the updated solution in favor of Icon object with documentation.

Use Icon object

var icon = {
    url: "../res/sit_marron.png", // url
    scaledSize: new google.maps.Size(50, 50), // scaled size
    origin: new google.maps.Point(0,0), // origin
    anchor: new google.maps.Point(0, 0) // anchor
};

 posicion = new google.maps.LatLng(latitud,longitud)
 marker = new google.maps.Marker({
  position: posicion,
  map: map,
  icon: icon
 });

Solution 3:

MarkerImage has been deprecated for Icon

Until version 3.10 of the Google Maps JavaScript API, complex icons were defined as MarkerImage objects. The Icon object literal was added in 3.10, and replaces MarkerImage from version 3.11 onwards. Icon object literals support the same parameters as MarkerImage, allowing you to easily convert a MarkerImage to an Icon by removing the constructor, wrapping the previous parameters in {}'s, and adding the names of each parameter.

Phillippe's code would now be:

 var icon = {
     url: "../res/sit_marron.png", // url
     scaledSize: new google.maps.Size(width, height), // size
     origin: new google.maps.Point(0,0), // origin
     anchor: new google.maps.Point(anchor_left, anchor_top) // anchor 
 };

 position = new google.maps.LatLng(latitud,longitud)
 marker = new google.maps.Marker({
  position: position,
  map: map,
  icon: icon
 });