When assigning image/jpeg to the "file format:" pull-down for a wms layer and then displaying the layer the format is changed [#810134]

When assigning image/jpeg to the "file format:" pull-down for a wms layer and then displaying the layer the sites/all/modules/openlayers/OpenLayers-2.9.1/OpenLayers.js file changes the format from image/jpeg to image/png. I have temporarily fixed this by finding the 2 places where /OpenLayers.js changes image/jpeg to image/png by preventing this from happening. Somehow what is passed to /OpenLayers.js as far as the format is interpreted as needing to change from image/jpeg to image/png. When I use openlayers outside of Drupal and the openlayers module and pass a format of image/jpeg to openlayers it does not change it to image/png.

Below is the area that I had to modify within /OpenLayers.js:
if(this.params.FORMAT=="image/jpeg"){this.params.FORMAT=OpenLayers.Util.alphaHack()?"image/gif":"image/png";

Comments

Comment #1

tmcw CreditAttribution: tmcw commented 26 May 2010 at 18:14

Category:

bug

» support

Is your WMS layer set as transparent? If it is, then OpenLayers will change the format to png, because jpegs can't be transparent. The relevant chunk of code is around the part you changed:

        if (!this.noMagic && this.params.TRANSPARENT && 
            this.params.TRANSPARENT.toString().toLowerCase() == "true") {
            
            // unless explicitly set in options, make layer an overlay
            if ( (options == null) || (!options.isBaseLayer) ) {
                this.isBaseLayer = false;
            } 
            
            // jpegs can never be transparent, so intelligently switch the 
            //  format, depending on teh browser's capabilities
            if (this.params.FORMAT == "image/jpeg") {
                this.params.FORMAT = OpenLayers.Util.alphaHack() ? "image/gif"
                                                                 : "image/png";
            }
        }