change optpix setting option>alpha channel settings>select half range 256 colors
now just click create new alpha channel and it will be set to 128 of course if the image have already set an alpha channel first delete it this will make the full image alpha to 128 so there will not be transparency what i recomend to you is to just save you image as png-8(save for web and devices) 256 colors and no background open the image i optpix look what palette number is the one with the alpha set to 0 make the process i posted before and when you have the alpha set to 128 just change the alpha back to 0 on the corresponding palette number
now just click create new alpha channel and it will be set to 128 of course if the image have already set an alpha channel first delete it this will make the full image alpha to 128 so there will not be transparency what i recomend to you is to just save you image as png-8(save for web and devices) 256 colors and no background open the image i optpix look what palette number is the one with the alpha set to 0 make the process i posted before and when you have the alpha set to 128 just change the alpha back to 0 on the corresponding palette number
