Mfcttrf

I want to write a binary raster to disk. I have the numpy array whose dtype is:

dtype('bool')

I try to open a GTiff for writing:

img_output = rasterio.open(
 "../../binary_output.tif",
 'w',
 driver='GTiff',
 nodata=nd,
 height=self.raster.height,
 width = self.raster.width,
 count=1,
 dtype = binary_raster.dtype,
 crs=self.raster.crs,
 transform=self.raster.transform,) 

But I end up with:

TypeError: invalid dtype: 'bool'

I have also tried things like:

dtype = bool
dtype = 'bool'
dtype = "bool"

What is the problem with this? According to the docs, dtype can be any numpy dtype. How do I write a binary raster?

If you call rasterio.dtypes.check_dtype(np.bool_) you'll see that it's not a known dtype, because gdal doesn't support a true 1-bit dtype. GDT_Byte is the smallest. The list that rasterio is checking against is:

dtype_fwd = 
0: None, # GDT_Unknown
1: ubyte, # GDT_Byte
2: uint16, # GDT_UInt16
3: int16, # GDT_Int16
4: uint32, # GDT_UInt32
5: int32, # GDT_Int32
6: float32, # GDT_Float32
7: float64, # GDT_Float64
8: complex_, # GDT_CInt16
9: complex_, # GDT_CInt32
10: complex64, # GDT_CFloat32
11: complex128 # GDT_CFloat64

uint8 and int8 are mapped to the ubyte, as seen here:

https://github.com/mapbox/rasterio/blob/master/rasterio/dtypes.py#L29-L45

Yes, you can write a one bit raster with rasterio*.

You need to:

1. write to a format that supports a 1bit dataset, such as GeoTIFF;


2. ensure your numpy array is np.uint8/ubyte so rasterio doesnt raise the TypeError: invalid dtype: 'bool' exception; and


3. pass the NBITS=1 creation option to tell the underlying GDAL GeoTIFF driver to create a one bit file.

import numpy as np
import rasterio as rio

with rio.open('test_byte.tif') as src:
 data = src.read()
 profile = src.profile

with rio.open('test_bit.tif', 'w', nbits=1, **profile) as dst:
 dst.write(data)
 # If your array is not a byte dtype, you need to cast it as ubyte/uint8
 # dst.write(data.astype(np.uint8))

$ ls -sh test_bit.tif
228K test_bit.tif

$ ls -sh test_byte.tif
1.8M test_byte.tif

$ gdalinfo test_bit.tif
Driver: GTiff/GeoTIFF
Files: test_bit.tif
Size is 1588, 1167
<snip...>
Band 1 Block=1588x41 Type=Byte, ColorInterp=Palette
 Image Structure Metadata:
 NBITS=1

$ gdalinfo test_byte.tif
Driver: GTiff/GeoTIFF
Files: test_byte.tif
Size is 1588, 1167
<snip...>
Band 1 Block=1588x5 Type=Byte, ColorInterp=Gray

* whether or not any software other than GDAL based can read it, I don't know...