1

As mentioned in the title i need to integrate a raster to a satellite image but have no idea as to how to do this. I tried the add grid function and it works nice but is not permanent. I insert it via map composer but as this inhibits zooming I need to save it on the image. The person who will use the image as a map wishes to be able to zoom just as in any image. How is it possibly to permanently add the a raster with 10 square kilometre grid size permanently to a satellite image I have as TIFF format?

  • To clarify, you want to add a grid of lines on top of an image for reference? – wildintellect Jul 15 '14 at 8:14
  • exactly this is what I want to do – kwai Jul 15 '14 at 12:48
  • I removed my answer because I did not understand the question. I suggest that you create your grid in the print composer, then you export this map (image + graticule grid) as an image. docs.qgis.org/2.0/en/docs/user_manual/print_composer/… – radouxju Jul 15 '14 at 16:00
  • Amazing forum! i was able to find other solutions regarding to raster as i read all the comments above. Satellite imagery is really awesome and very useful. I appreciate all of your efforts to share your ideas to this one. Kudos to you all! Daniel - TerraServer – user37414 Sep 25 '14 at 2:42
2

The problem you have to solve is that a vector grid is displayed in a scale-independent pixel size, while a raster image is defined by a fixed cell size.

You could rasterize your vector grid, and merge it with the satellite image, but zooming out the grid will get smaller until it can not be seen anymore.

The other way round, a 10km, 1-pixel-wide grid will lead to a screen full of lines hiding the satellite image completely.

So you can only make a grid for a most wanted scale.

  • thanks for the answer. so what steps would i need to do in order to vectorize the raster image and add a the grid? i use qgis and am quite new – kwai Jul 16 '14 at 20:41
  • I rather thought of rasterizing the vector grid. QGIS has a built-in rasterizer under Raster -> Conversion -> Rasterize, as well as a merge tool using gdal_merge. – AndreJ Jul 17 '14 at 5:52
  • yes, but the main problem i have is that i do not know where to take the grid from and rasterize it. I used View- Decorations-Grid but this does not save the grid as a vector anywhere. Where can i get it or how an i produce it in qgis? – kwai Jul 17 '14 at 6:46
  • I use Vector -> Research Tools -> Vector grid. This creates a permanent shapefile. – AndreJ Jul 17 '14 at 6:50
  • thanks, it worked nicely but when now rasterizing the vector grid using the above described method the outcome is only black. i tryed to adjust using properties-style- singleband pseudocolor. i can start to see lines but as the whole area is covered i can not see the original satellite image underneath. and thus i can not merge the two.what am i doing wrong? – kwai Jul 17 '14 at 7:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.