ONE Trick to Improve Your Photogrammetry

how do you take a point Cloud that looks like this one it's full of holes it's Overexposed you would never want to hand it over to a client and turn it into this holes are gone the color is balanced so much better now but how for that same meta this author image atrocious you wouldn't want it how do you turn it into this one you might say my images they were too bright when I captured them or maybe I had a lot of cloud Shadow I can't control that what you need to do is go to Google and look up raw therapy first result that comes up click on the downloads page let it open and then choose the one that is applicable to your system download and install it it's free of charge once that's done open it up on the left hand side of the screen go to the folder where all of your drone images are stored they've all come up in the center of the screen scroll down a bit to an image that you know is not looking the best open that one up next step is simple you might say well yes it's Overexposed so I'm just going to edit the exposure here on the right hand side so you go to the exposure you bring it down a bit all it does is make things darker then you just don't look any better you can't send more details exposure isn't the answer in this case so let's get rid of that and what you want to focus on is a really good tool on the bottom right hand side of the screen shadows and highlights that's going to change the way you do photogrammetry first step we're going to activate the Shadow and highlights tool then pay attention to the Overexposed white areas as we drag the highlights tool to its Max back to its minimum can you see how the details are starting to become apparent within the imagery now even though the reflections are really really bright by using this tool we can bring out the information that is stored there you might then say well what's the purpose of the Shadow tool so we're going to move away from the highlights and go to a darker area and let's now play with the shadow tool pushing it up all the way to the maximum and then coming back a bit down the maximum does over expose it a bit so I want to bring it back down let's say about halfway so now we've got our highlights all the way to the Max and Shadow about 50 percent go back to your first area make sure that the shadow setting you are using isn't destroying the area we've just corrected in highlights what you want to do now is copy those settings then go to any other image you have in your list we're going to apply those settings and see if it still works on another image so take a look at this image now and we're going to hit the apply button on the top right hand side and it still looks pretty good once we've made that application let's go look at another image one that has a bit more detail to look at once you've found one open it up same thing hit the apply button again and look at the result much better so if you're happy with the result we want to select all of the images and this is the beauty of a tool like raw therapy is that we can apply the same setting to all the images in a batch mode firstly select all of them and then we want to go to our tools and paste that setting give it a moment and it'll apply to all the images easy as that again select all the images and send them to the queue for processing then all you need to do is go to the queue you then want to specify the output folder that you're going to send those images to make a new fold if that suits you give it a name whatever helps you identify it is fine and once that's done you're then going to select your image output settings raw therapy has a few options to choose from over here select whatever you are happy working with just your jpeg quality image quality as well and the last step is to just output those images on the left hand side so what's the point of all of this the results speak for themselves use any photogrammetric processing software that you are comfortable with we're going to compare them side by side now on the left hand side no edits have been done and on the right hand side shadows and highlights have been applied can you see these very bright areas how much more information we can see on the right hand side now as we pan across pay close attention especially now to this roof how much more data is evident on the right versus what you see on the left let's zoom in into another roof here yes on the left hand side you can see some detail but wouldn't you prefer the image on the right hand side there's just so much more to choose from zooming into this road can you actually compare the difference on the left hand side to the right hand side the cracks in that road just pop out now it's fantastic how good using a tool like this really is but what about Shadows we've looked at highlights so zooming into an area we want to focus on the Shadows that the trees have cost remember we only use the 50 setting so we see some improvement not very dramatic but pick the scenario that works for you looking at this pavement as well look at these flagstones so much more info is evident here let's compare the point Cloud because this is really getting into the nitty-gritty as we zoom in on this roof it's shocking the result we've got on the left hand side but look at that dramatic Improvement on the right hand side just because we edited our images it's astonishing but this is the Crux of the meta we're going to draw a cross section now and compare the two data sets alongside each other on the left hand side the red unedited and on the right hand side the blue edited look at the mess of that red surface and why don't we like this accuracy we want our data to be accurate at all times let's take a look at some other areas and compare cross sections as well what about on the pavement that we had a look at earlier we're going to go back to that same area and draw a cross section again how will they compare this time well we draw that section we're going to change the color again left hand side is going to be red the right hand side edited is blue and as we zoom in the first thing we notice is there's now an elevation difference between the two surfaces now we don't really want that that just tells us that there's inaccuracy but as well look at the larger spread of the red points far worse than the Blue Points let's go to a third area perhaps the main road down the middle of our data we expect that to be nice and flat don't we let's see how the two compare so we're going to draw another cross section now these cross sections only half for me to wide by the way cross-section we're going to change the colors again so that we can compare our two surfaces to each other and although what we're going to notice in this case is that generally they both look quite clean again notice the elevation difference between the two if we are getting an elevation difference purely because we've made our images better on the right hand side is that not something you should be doing to every one of your projects so remember if this is something you want to do if you want to improve your photogrammetry get any tool that allows you to apply Shadow and highlight settings and if you want to learn how to process photogrammetry why not have a look at these two videos foreign

Channel: Geospatial Tips

Views: 21,970

Keywords: Agisoft, Metashape, Drone, UAV, Photogrammetry, 3D Model, Contour, DJI, Pix4D, Drones, Volume Caculations, TerraScan, TerraModeler, Global Mapper, Survey, agisoft metashape, photogrammetry, agisoft photoscan, terrasolid, mine surveying, dji mavic, dji mavic mini, dji mavic mini 2, dji mavic mini 3, drone, agisoft metashape tutorial, qgis, arcgis pro, lidar, rawtherapee, lightroom, image editing, 3d modelling, metashape, shadows and highlights, adobe lightroom, fix drone imagery, drone mapping

Id: kI-jJUr9rH8

Length: 8min 12sec (492 seconds)

Published: Sat May 06 2023