Automate process of creating a mask
ts@...
Dear Rasterios,
beeing quite new to rasterio I'm looking for help regarding the following: I've a large amount of 1 Channel Satellite imaginary. While the data contains no-data information around the actual motif nearly black areas do exist which I'd like to cleanup. Following the docs masking by shapefile It perfectly works to crop my image to the desired image area: The red shape is quite inaccurate drawn just for the purpose of testing! My question now is, how can I automate the creation of a shapefile to mask with based on the grey value or a defined border within my data? Having a closer look on the edge of my desired image area my problem should get clear. The border is fuzzy, further the nearly black pixel value could exists in the desired motif. I'm thankful if you could show me a direction to automate the creation of a shape mask (or geojson which should work as well from what I read at docs)! – Toni
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Re: rasterio opens file from AWS S3 bucket on local machine, but can't find file when deployed to Google App Engine
Sean Gillies
Hi Judson, On Wed, Aug 12, 2020 at 9:42 AM Judson Buescher <judson.buescher@...> wrote:
If the source data for your App Engine app is on AWS, you'll need to make sure that you're providing AWS keys to access it. You'll want etc. in your environment, not GS_SECRET_ACCESS_KEY (etc.). I've never used boto3 on App Engine and wouldn't recommend that approach of configuring AWS for GDAL and rasterio. Sean Gillies
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Re: rasterio opens file from AWS S3 bucket on local machine, but can't find file when deployed to Google App Engine
judson.buescher@...
Hi Sean,
rasterio==1.1.5
in the requirements.txt. For the credentials I’ve tried a couple different ways. I’ve tried setting them using
os.environ['GS_SECRET_ACCESS_KEY'] = secret_access_key os.environ['GS_ACCESS_KEY_ID'] = access_key
I’ve also tried
session = boto3.Session(aws_access_key_id=access_key, aws_secret_access_key=secret_access_key)
and then using that session object when I open the raster file. Was there any other info you’d like?
From: <main@rasterio.groups.io> on behalf of "Sean Gillies via groups.io" <sean.gillies@...>
Apologies for the late reply. There may be a bug, yes, but there are more likely sources of trouble. Can you explain more about how you are installing the rasterio package on GCP and how you are configuring your AWS credentials?
On Thu, Jul 23, 2020 at 7:06 AM <judson.buescher@...> wrote:
--
Sean Gillies
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Re: window_transform doesn't produce accurate coordinate transforms
pranay1117@...
Hi Sean, thanks for your reply - that was indeed the source of the issue on my end. I was able to fix it!
-- Best, Pranay
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Re: Reprojecting output image to input image crs where the image sizes differ
Sean Gillies
Hi, On Tue, Jul 21, 2020 at 11:52 PM <ashnair0007@...> wrote: I have a geotiff (size= 4490 x 7341) that I cut into 256 x 256 crops to do an operation. Once the operation is done, I merge them back together. Since the original dimensions aren't divisible by 256 the resulting image will be of size 4608 x 7424. However the output tif and the input tif are of the same location, so they need to be geo-referenced the same. Is it possible to do so? Sorry about the late reply. I hope it is still useful. Sean Gillies
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Re: window_transform doesn't produce accurate coordinate transforms
Sean Gillies
Hi, Hi, I'm new to rasterio and working with geographical data. So far, it's been a great experience working with this library - but I've run into an issue when working with the Window module. My use case is as follows: Your usage of the affine transform affine_transform * (r-1, c-1) is incorrect. You must swap the order of the tuple indexes to get the correct results because mathematically speaking (x', y') = affine_transform * (x, y) and row is y and column is x. Rasterio has a method that will help keep this straight: https://rasterio.readthedocs.io/en/latest/api/rasterio.transform.html#rasterio.transform.xy. The ordering of items in (row, col) versus (x, y) is a constant source of confusion. I hope this reply hasn't come too late and that it is useful. -- Sean Gillies
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Re: rasterio opens file from AWS S3 bucket on local machine, but can't find file when deployed to Google App Engine
Sean Gillies
Apologies for the late reply. There may be a bug, yes, but there are more likely sources of trouble. Can you explain more about how you are installing the rasterio package on GCP and how you are configuring your AWS credentials?
On Thu, Jul 23, 2020 at 7:06 AM <judson.buescher@...> wrote:
-- Sean Gillies
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Re: returning subset of raster data via API
Sean Gillies
On Wed, Aug 5, 2020 at 5:41 AM Tom Kralidis <tom.kralidis@...> wrote:
You're welcome. It's unfortunate that we don't have a more informative message from GDAL that we can raise to users. "No such file or directory" is too opaque. Sean Gillies
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Re: returning subset of raster data via API
Per https://gdal.org/user/virtual_file_systems.html#drivers-supporting-virtual-file-systems and confirmed by Even R, GDAL's NetCDF
driver cannot write to Thanks again for the clarifications.
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Re: returning subset of raster data via API
Sean Gillies
Hi Tom, On Mon, Aug 3, 2020 at 5:32 PM Tom Kralidis <tom.kralidis@...> wrote:
-- Sean Gillies
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Re: returning subset of raster data via API
(sorry, just getting back to this!) Thanks Sean. Indeed the MemoryFile strategy works as expected:
Are there any known issues with reading/subsetting, and writing back a NetCDF via MemoryFile? Traceback:
Versions:
Thanks ..Tom
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Re: How to extract DATA_ENCODING creation option type from an input grib2 file for use in the output grib2 file
Thanks Shane/Sean. On the pygeoapi side, I also stumbled on this issue and was able to allow for user specific options in configuration and passing that on to rasterio accordingly. Definitely not dynamic, but worked for me, at least from the perspective of consistent (enough) production of GRIB2. Cheers ..Tom
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window_transform doesn't produce accurate coordinate transforms
pranay1117@...
Hi, I'm new to rasterio and working with geographical data. So far, it's been a great experience working with this library - but I've run into an issue when working with the Window module. My use case is as follows:
- I obtain 2 bounding coordinates from the user (top-left and bottom-right) and convert them to (row, col) using `source.index(lon, lat)`. - I create a window using these bounds and read the dataset from that. Also, I get the appropriate transform for this window. selected_window = Window.from_slices((row0, row1), (col0, col1))
data = src.read(1, window=selected_window) affine_transform = src.window_transform(selected_window) Afterwards, I am using this `data` numpy array to select various points in these bounds and plot them on a map. However, the (lat, long) coordinates obtained using the affine_transform above are not very accurate. When I run the following: print("Lat/Lon bounds: {}".format(src.window_bounds(selected_window)))
print("Transform at (0,0): {}".format(affine_transform * (0,0))) r, c = data.shape print("Transform at {}: {}".format((r-1, c-1), affine_transform * (r-1, c-1))) The output is as follows: Source lat/lon bounds: (72.45 20.69, 82.39, 28.78)
As is evident from the output, the latitude must lie between (20.69,28.78) but the transform value 18.841 at (970, 1193) is not in that interval. Transform at (0,0): (72.42, 28.78) Transform at (970, 1193): (80.53, 18.841) I saw some earlier posts in this group that suggested updating to version 1.1.5. I've done that but the issue persists. Any help will be greatly appreciated. Thanks!
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rasterio opens file from AWS S3 bucket on local machine, but can't find file when deployed to Google App Engine
judson.buescher@...
Hello,
I'm trying to run a python flask app, that opens a file hosted on an S3 bucket and analyzes the data. When I deploy the flask app on my local host, it runs like expected. Once I deploy the app to the cloud, it suddenly cannot find the file. I feel like this might be a bug, but i'm too afraid to post in the github. I'll attach the relevant snippet of code, and the error I'm receiving in the GCP Logs. I apologize for terrible formatting as I'm unaware of how to do it properly in this forum. and here's the error:
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Re: Reprojecting GEOTIFF to epsg:3857 with scrambled CRS data (possibly GCJ-02)
Even Rouault
On mardi 21 juillet 2020 18:52:10 CEST toku2288 via groups.io wrote: > Hi, Just an update. Turns GeoTIFF does use GCJ encoding, However, There seem > to be some open-source projects online which can reverse the transformation > to high accuracy, Is there some way to use this algorithm to reproject the > GeoTIFF file?
This had been discussed for PROJ in https://github.com/OSGeo/PROJ/issues/982
Summary: apparently technically doable, but for legal reasons for folks operating in China, cannot be included in PROJ.
-- Spatialys - Geospatial professional services http://www.spatialys.com
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Reprojecting output image to input image crs where the image sizes differ
ashnair0007@...
I have a geotiff (size= 4490 x 7341) that I cut into 256 x 256 crops to do an operation. Once the operation is done, I merge them back together. Since the original dimensions aren't divisible by 256 the resulting image will be of size 4608 x 7424. However the output tif and the input tif are of the same location, so they need to be geo-referenced the same. Is it possible to do so?
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Re: Reprojecting GEOTIFF to epsg:3857 with scrambled CRS data (possibly GCJ-02)
toku2288@...
Hi, Just an update. Turns GeoTIFF does use GCJ encoding, However, There seem to be some open-source projects online which can reverse the transformation to high accuracy, Is there some way to use this algorithm to reproject the GeoTIFF file?
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Re: Convert BoundingBox data into lat/lon
toku2288@...
Hi Guillaume,
Thanks, It worked. I previously tried using the CRS EPSG:3857 using that method, and it returned lat/lon values out of range. Is there some way to get the EPSG:3857 values?
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Re: Convert BoundingBox data into lat/lon
Guillaume Lostis
Hi, The rasterio.warp.transform_bounds function should do what you want: https://rasterio.readthedocs.io/en/latest/api/rasterio.warp.html#rasterio.warp.transform_bounds Pass it the CRS of your dataset as src_crs, CRS({'init': 'EPSG:4326'}) as dst_crs, and your bounds, and you will get your bounds in lon/lat as output. Regards, Guillaume Lostis
Hi, I need to convert the bounding box data of a TIF file to lat/lon co-ordinates so I can request data from another API
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Convert BoundingBox data into lat/lon
toku2288@...
Hi, I need to convert the bounding box data of a TIF file to lat/lon co-ordinates so I can request data from another API
GridTIF.bounds returns a BoundingBox object like the following: BoundingBox(left=-2638055.0614613006, bottom=340165.4847189281, right=2410944.9385386994, top=5922165.484718928) Is there some way to convert this to lat/lon of the two corners in it's current CRS?
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