[OpenLayers-Users] Aspect Ratio/Projection Problem

Fri Jun 6 10:57:14 EDT 2008

The options at that time was just {} now it as this.

Now it is as the following, still behaves the same....

            var options = {
                projection: new OpenLayers.Projection("EPSG:900913"),
                displayProjection: new OpenLayers.Projection("EPSG:4326"),
                units: "m",
                maxResolution: 156543.0339,
                maxExtent: new OpenLayers.Bounds(-20037508, -20037508,
                                                 20037508, 20037508.34)
            };

    g_map = new OpenLayers.Map('map', options);

	var mapbounds = new OpenLayers.Bounds(-74.766667,
			39.166666667,
			-71.88333,
			40.88333)
	var graphic = new OpenLayers.Layer.Image(
			'Oceantemp.com Temperatures',
			'http://www.rowdylabs.com/gmaps/oceantemp/area-ne06.gif',
			mapbounds,
			new OpenLayers.Size(1030,796),
			{maxExtext:mapbounds});

	g_map.addLayers([graphic]);
	g_map.setCenter(new OpenLayers.LonLat(-73,40), -1);

	g_markers = new OpenLayers.Layer.Markers( "Markers" );
	g_map.addLayer(g_markers)

On Fri, Jun 6, 2008 at 8:09 AM, Paul Spencer <pagameba at gmail.com> wrote:
> Michael,
>
> I tried your code, you have omitted a critical piece which is the options
> object you are passing to the map constructor - please send so I can see
> what is going on.
>
> Cheers
>
> Paul
>
> On 6-Jun-08, at 3:33 AM, Michael Langford wrote:
>
>> I tried Paul's suggestion and it didn't change anything.
>>
>> I'll try to clarify and add code.
>>
>> If you take OpenLayers out of the picture entirely, and you use GMaps
>> instead to do what we're trying to do, you'd use a GGroundOverlay on
>> google maps to plop say a custom map of New York City down on top
>> (completely obscuring their map). When you do this, the google does
>> not in any way stretch, modify, reproject, etc, the images we are
>> using. It might with other images, but ours come out the same as they
>> go in, probably indicating we have the same projection as Google Maps,
>> or at least close enough these areas overlay correctly. Here is an
>> example of using GGroundOverlay:
>> http://www.usnaviguide.com/ws-2008-02/ggroundoverlay_example.htm
>> Notice his picture *IS* reprojected to fit on the google map (ours is
>> not).
>>
>> If we port our GGroundOverlay example from GMaps to open layers, we
>> throw down our custom map of say New York, then OpenLayers decides (at
>> least in the default setup), that it would like to stretch our custom
>> map overlay. Sure, it reports the correct lats and longs after doing
>> so, but it looks horrible, as there is lots of lettering and symbols
>> on the map which are stretched to near illegibility. We want to mimic
>> the projection that the screen map is in on Google Maps so as to avoid
>> any distortion.
>>
>> When we use an OpenLayer.Layer.Image on top of the default map that
>> you get when you go new OpenLayers.Map("map"), the picture is
>> distorted as OpenLayers reprojects the image or something like that,
>> elongating it in the east west direction.
>>
>> How can I use an image layer in OpenLayers to achieve the same
>> appearance as a GGroundOverlay in google maps, with no squishing and
>> stretching of the image overlay?
>>
>> As a further modification, we're actually just using the image as the
>> base map. We're not using a google map, WMS server or anything like
>> that, nor are we tiling our image. We're justing using the single
>> image that we were overlaying now as the "base layer" of the map.
>> We're just interested in the controls, markers, and nice map
>> pixel->coordinate translations, as well as your wonderful vector
>> drawing api.
>>
>> Remember when I say terms like "base layer" etc, I probably don't have
>> the same OpenLayers concepts you do, and I just mean its the map on
>> the bottom, we're not putting any pictures under it. Sorry if I used
>> terms different than they are in the Open Layers community.
>>
>>         --Michael
>>
>> Here is the code that initializes the map:
>>        var mapbounds = new OpenLayers.Bounds(-74.766667,
>>                        39.166666667,
>>                        -71.88333,
>>                        40.88333);
>>
>>     g_map = new OpenLayers.Map('map', options);
>>
>>        var graphic = new OpenLayers.Layer.Image(
>>                        'Overlay of Temperature Data',
>>
>>  'http://www.rowdylabs.com/gmaps/oceantemp/area-ne06.gif',
>>                        mapbounds,
>>                        new OpenLayers.Size(1030,796),
>>                        {maxExtext:mapbounds});
>>
>>        g_map.addLayers([graphic]);
>>        g_map.setCenter(new OpenLayers.LonLat(-73,40), -1);
>>
>>        g_markers = new OpenLayers.Layer.Markers( "Markers" );
>>        g_map.addLayer(g_markers);
>>
>>
>> On Fri, Jun 6, 2008 at 2:22 AM, Eric Lemoine <eric.c2c at gmail.com> wrote:
>>>
>>> On Fri, Jun 6, 2008 at 12:43 AM, Michael Langford
>>> <michael.langford at rowdylabs.com> wrote:
>>>>
>>>> After switching to openlayers.org from google maps, we're almost ready
>>>> to launch my customer's new site.
>>>>
>>>> One problem though: His overlay image is "squished" on OpenLayers,
>>>> where it looks great using the image overlay of Google Maps API. It
>>>> involves way too many hours of hand lettered text on it to contemplate
>>>> redoing in the new aspect ratio, so I need to find a technical
>>>> solution to make OpenLayers.org display it properly.
>>>>
>>>> I've been fiddling with projections, and have not seen a way out of
>>>> this forest, as nothing appears to change the display of the image.
>>>>
>>>> When I look, I keep finding pointers on the web to the extremely brief
>>>> comment about projections on the FAQ, which doesn't help me at all.
>>>>
>>>> It seems like I'd like to display in EPSG:900313 as that is what
>>>> Google uses (that may not be the exact name, I deleted it after it
>>>> seemed clear it wasn't working).
>>>>
>>>> I'm not exactly sure the role the proj4js plays in this, but it seems
>>>> like it probably does.
>>>>
>>>> I've attached the picture of what the overlay looks like when applied
>>>> to google's map, and what the overlay looks like when applied to open
>>>> layers. In addition, it is available at
>>>> http://rowdylabs.com/ng/RightAndWrong.GIF in case the mailing list
>>>> doesn't like attachments.
>>>>
>>>> Hopefully someone can provide something like the following:
>>>>
>>>>  You properly include proj4js at the top of your html file like so,
>>>> and you create your map with arguments like so.
>>>
>>> Hello
>>>
>>> I'm not sure I understand your problem. But if what you want is have
>>> overlays over google maps you'll need to use SphericalMercator. See
>>> some doc here <http://trac.openlayers.org/wiki/SphericalMercator> and
>>> some example there
>>> <http://www.openlayers.org/dev/examples/spherical-mercator.html>. Hope
>>> this will help you do what you want.
>>>
>>> Cheers,
>>>
>>> --
>>> Eric
>>>
>>
>>
>>
>> --
>> Michael Langford
>> Phone: 404-386-0495
>> Web: http://www.RowdyLabs.com
>> _______________________________________________
>> Users mailing list
>> Users at openlayers.org
>> http://openlayers.org/mailman/listinfo/users
>
>

-- 
Michael Langford
Phone: 404-386-0495
Web: http://www.RowdyLabs.com