[Gdal-dev] Constant width using gdalwarp?

[Seth Price]

Let me start off by saying that GDAL is excellent. Big thanks. :)

I am reprojecting a set of 14400x14400px lat/long images to 14400px  
wide, and the image height depends on the latitude. The output  
projection is Mercator. My intent is to only interpolate pixels in  
one direction, so the output image will be a bit sharper along the x  
direction.

I thought I could do this with the "-tr" flag, but the width is  
changing depending on the latitude. Out of the two latitudes I've  
tried, I'm getting images 14400px wide and 14399px wide.