Making your own photoscenery using free tools

[toprob]

This is something I've promised for a while, showing how to make your own photo scenery based on the LINZ images, using free tools only.
Of course this assumes that you have the simulator SDK installed (any version would do, I recommend the FSX version for the widest compatibility.)
I've done this as a video as this is the quickest way, no copy/paste screenshots or text, just record it and upload it. However it does need to gloss over some areas, so please consider it as an ongoing discussion here in this thread. I did aim for 20 minutes, and managed 24, whereas my first attempt was 45 minutes...
I hope the sound is ok, as I don't have a microphone, I recorded to my phone, then uploaded to Onedrive -- it seems to have worked as expected. This is best viewed in 1080p on YouTube, so that you can see what's going on. I'll post any referred links below the video.
I can cover some extra steps such as colour-correcting and water masking if there is a demand.

Watch on youtube.com

LINZ Data Service
QGIS open-source Geographic Information System
GeoTIFF to Inf tool
GIMP imaging software

[Ian Warren]

GREAT little video Rob , if I see Cricket Balls coming my way I know your only just down the road, ..... I have still stuck to VLC only to finish many areas that require AGN , good thing here is, you also including a river as well for the water masking .. only half way thru the video . but starters very intuitive and helpful.

[toprob]

Watching it through for the first time, I'm very aware of the warts-and-all style:} I was determined to get this is one take, after a previous attempt a week ago when I lost one of the audio files. So here I've left in the bits like when I accidentally started up my TV stream. I normally never watch the Block...
I've just this week switched to the Edge browser, following the Windows anniversary update, and I love its nice quick clean look here.
I did mention the tool I use to extract and put back the geodata, here's the link to the download site, it's the line which reads:
A contributed win32 gui for listgeo is available at ​ftp://ftp.remotesensing.org/geotiff/libgeotiff/listgeo_GUI.zip.
....and the page is http://trac.osgeo.org/geotiff/

If you have installed the SDK, then you will have a folder called Resample Examples, with all the info you'd need to create your own INF file. I make it seem a bit easier than it is to run Resample, that's because I have a shortcut on my Desktop and I just drag INF files -- normally with a txt extension because I'm lazy -- onto the shortcut. When I updated Windows this week I fiddled with the text sizes which explains why my desktop icons all shifted, and I had to go looking for the Resample shortcut which has been in the same place for years now:)

[Ian Warren]

I think this gives some newbies the opportunity to give areas not touched, to hook in there and do it and specific if their home town is not done , you can't say here you don't the Pro's to help them out in both fields, the photo placement and the autogen.

[Riddlez]

It's nice to hear a kiwi accent again lol.

Great video I learned a lot off it, I feel like I owe you a beer for all this help you've been giving us

For areas that are small like Balclutha, and I've done the same for some parts of Taranaki, one big tiff file that is linked to the INF file is enough. Infact I stitch them together manually in Photoshop, colour correct them while I'm there and add the top left and bottom right information to the INF file. Until now I didn't know there was a quicker way. Working out the xDim and yDim is a pain in the arse though lol. Anyway, for huge regions like what I want to do for Taranaki, one big file will be impractical. It would be 100,000s of pixel in size if not millions. So I guess splitting the files will be the next best option. My question to you is how do you do that? Do you have multiple Geotiffs/image files linked to one INF file, with each of their respective coordinates in the INF file. Or is it one Geotiff/image per INF file? Or is there another way to do it?

[toprob]

A good question, it is on the list of what I could cover in future tutorials.
The limiting factor for me is the tool I use to extract/restore the geo data -- this is an older tool which can't cope with huge files, so I tend to keep individual TIFF files 2GB or under. This means that a typical larger photoscenery can include a lot of sources in one INF -- The Dunedin scenery for instance includes 5 major photoscenery BGLs, with a total of 52 source files so far, not counting the two higher resolution airports.
I tend to divide an area up into chunks that make sense to me, but probably won't make sense to anyone else.

[Riddlez]

Ah awesome I see what you mean. I'm glad that I can put multiple areas in one INF file. I was dreading resampling multiple INF files for each of the areas I split up. I just hope it works without adding seams between the different images.

[NZ255]

Nice vid Rob.
It's funny when you hear a person for the first time. You don't sound anything like the voice I've given you from reading your posts over the years

if you have one large source file you can tell the inf to split the output into lod or quid sections.

But the problem is working with a massive high res image to edit. Plus the 2GB limit as Rob says.
If you can, don't save the tiff compressed. Yes it'll be a larger file size but then the resample.exe has to uncompress it first which slows down the resample process a lot.

[toprob]

Cheers, Nick. You've touched on the features of Resample, which is an amazing little tool, my 'basic' INF barely skims the surface.
I use Global Mapper rather than QGIS to join my images, and for larger areas Global Mapper will slice the image into however many bits I want, by entering the number of rows and columns. I suspect that QGIS can do the same. So I end up with a matrix of images, e.g. 2x2 or 3x4 etc. This gives me a few big tiles made from hundreds of tiny tiles, and these are edited separately, and only put back together when I create the scenery BGL using Resample.

Some info about combining images -- the way I do it, the tiles align perfectly, so there's no need to consider any misalignments, but you could have individual images within a single INF overlapping, they will still build just one final photoscenery.

For abutting INFs, I like to have a little bit of overlap if I've done a couple of separate downloads, which I normally do. Sometimes I end up with a tiny gap where I've poorly estimated the overlap, so I just download the missing slice and include it in the INF to join it up. But that's because I'm not well-organised...

As download file size becomes an issue with larger scenery, I don't like to overlap too much, otherwise there more data than you actually need, but a little bit doesn't matter. You just need to make sure that these are colour-corrected exactly the same -- hence my use of Photoshop Actions, which record the actions when I first fix an image, then I can automatically apply the same adjustments to subsequent tiles. I did go looking for a way for GIMP to create macros, but haven't cracked that one yet.

So that's too things I need to find out, how to have QGIS easily slice the output GeoTIFFs, and how to record macros in GIMP... If anyone has any ideas, let me know.

P.S. Yeah, I sound like an old man now, which I suppose I am... plenty of um and arrs in there, but that's because I was a serious stammerer for 25 years, and only overcame it by learning various techniques to minimise it. Now I don't let it stop me from blathering on....

[Riddlez]

Cheers, Nick. You've touched on the features of Resample, which is an amazing little tool, my 'basic' INF barely skims the surface.
I use Global Mapper rather than QGIS to join my images, and for larger areas Global Mapper will slice the image into however many bits I want, by entering the number of rows and columns. I suspect that QGIS can do the same. So I end up with a matrix of images, e.g. 2x2 or 3x4 etc. This gives me a few big tiles made from hundreds of tiny tiles, and these are edited separately, and only put back together when I create the scenery BGL using Resample.

That's exactly what I need to learn how to do, so I don't have to do it by hand and keep it under the 2GB limit.

I've had a play around this afternoon, I downloaded the 1/8 res images from LINZ because I couldn't be bothered waiting for the bigger download and wanted to try it out quicker. I added 2 tiles from the download into FS. I quickly colour corrected one tile and left the other with the original colours. I'm quite happy with the results. I have the NZNI installed in the background. Some people think NZNI is a bit too brighter and saturated than real life. I have found from my experience that FSX and P3D are too desaturated which may give that illusion of over saturation. The native bush is a completely different colour in NZNI though, too brown. The aerial image is more accurate in that respect. The masking will make it look fantastic when it's all blended in. Everything lines up perfectly too which is fantastic!

[Ian Warren]

One thing I did notice with Mega scenery, A Free Ireland I scored on St Patrick's day , some of the regions also had a colouration change between tiles due photo's taken on different times and days, biggest thing is its photo real so that comes with the territory, trying to bleed the to different photo over such a large area would be a job in its self.

[toprob]

I did gloss over a few things in the video, including resolution, so I'll cover that in a bit more detail. Back in the early days of Godzone, the only aerial images available freely were supplied at 2.5 metres per pixel. This was fine back then, as FS2004 only displayed photoscenery at 4.8 metres per pixel, so we had all the resolution we could use. These days things have improved a lot, and now the simulator (FSX and Prepar3d) can comfortably display resolutions up to 7 cm for photoscenery. So we have to give some thought to what we want to end up with, which can affect the way we download and manage aerial images.

The 'default' landclass texture resolution is currently 1.2 metres per pixel (m/px). That's what you see in the default sim, and with addon landclass-type textures such as Orbx regions. So this is a good goal for large-scale areas, as it would appear at least as good as the default textures, with the added benefit of being based on the actual photo of the area depicted. However this assumes that the source images are of good quality, and not just a blurry mess.

So, what resolution do we want to end up with, and what do we start with?

One main factor is the resolution of the source imagery on LINZ. This averages around 40cm or 50cm/px, and can go as high as 8cm/px, and as low as 75cm/px. As I said in the video, you can choose to have LINZ reduce the resolution to make it more manageable, by a factor of two. So halving the resolution will reduce the 40cm/px image to 80cm/px, which reduces the actual download size -- and the finished scenery size -- to a quarter of the original size.

Now it might seem like a good idea to go for the supplied resolution, whatever that may be, and make the best looking scenery possible. However this can quickly add up to huge file sizes. If you are making scenery just for yourself, then it might not matter, until you start running out of disc space, but if you want to distribute the scenery to others, you need to aim for something which you can easily host, and which your users can easily download. Hosting is the main issue for freeware, although there are plenty of cloud storage options available for cheap or free, none of these really allow for large numbers of downloads, so putting it in the cloud would quickly result in a lock on your account when you exceed the accepted bandwidth limits.

Payware is a bit different, as you can factor in the bandwidth cost and use a cloud service which is happy to keep serving your files while you keep paying.

Freeware is probably best supplied via the existing freeware library sites, such as AVSIM. Currently they have a file size limit of 500MB, so this should be considered the top end of a freeware file size. Sure, you can try and figure out a way to distribute larger files yourself, and you may be able to serve a few, but believe me, you will run into problems with any popular addon.

So, what resolution is suitable? Some developers -- like me -- aim for a higher resolution airport photoscenery and a lower resolution large-scale photoscenery outside the airport. So this might be 30cm/px within the airport bounds, an 1.2m/px outside. Or if it is available, even higher for the airport, and maybe 60cm/px for a nearby city. Bear in mind that these figures are based on the simulators LOD grid, and these days I have a chart in my studio so I don't forget which LOD I'm working to. This goes from LOD 13, which is 4.75m/px, up to LOD 18, which is 15cm/px.

So it makes sense to download imagery as close to the final resolution as possible, while keeping it slightly higher resolution so that you are not building scenery of a certain LOD by having to make it bigger than the existing source, it's better to resample it down than up, otherwise you are increasing the file-size without a fully matching increase in quality. Note that today photoscenery can include part-LODs, so you will see the full quality of the actual source resolution if it doesn't match a LOD -- kind of a LOD-and-a-half approach, which keeps the quality high and the file-size higher than if you had to resample to a higher LOD. This will make more sense once you've made a few photosceneries...

[Ian Warren]

Rob .. lotta people ... most would say OH BUGGER THAT ! , we'd rather just pay for it ... true tho !

[toprob]

Two things grabbed my attention here, first there's 'lots of people..' then there's 'would rather just pay for it.' I just have to make that stick better.
Although out of 3.5 billion internet-users world-wide, I only have to get the attention of 2 or 3, and we'd be on a role!

[Ian Warren]

Although out of 3.5 billion internet-users world-wide, I only have to get the attention of 2 or 3, and we'd be on a role!

Hmm , same can be said for my artwork, of the near 7000 lookers .... had they brought one, I'd be 'Happy as Larry' .. and who the hell is this guy 'Larry' I think he's getting all the booty .. and were both missing out!