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I am using GDAL in Python to create a tiff raster of data that is originally from a shapefile. I have an auxillary data channel, which I would like to use to color the pixels of the tif. I have made sure that my data (yield_grid) is the same size and shape as my tif raster will be, but so far I am unable to get anything besides an all black square out of my raster.

Does anyone have a suggestion for what I might be doing wrong in assigning my data to my raster band?

# Define pixel_size and NoData value of new raster
pixel_size = 0.00005
NoData_value = -99

# Filename of input OGR file
vector_fn = inShapeFile

# Filename of the raster Tiff that will be created
raster_fn = 'test.tif'

# Open the data source and read in the extent
source_ds = ogr.Open(vector_fn)
source_layer = source_ds.GetLayer()
source_srs = source_layer.GetSpatialRef()
x_min, x_max, y_min, y_max = source_layer.GetExtent()

# Create the destination data source
x_res = int((x_max - x_min) / pixel_size)
y_res = int((y_max - y_min) / pixel_size)

# Get Driver and Create output target
target_ds = gdal.GetDriverByName('GTiff').Create(raster_fn, x_res, y_res,1,gdal.GDT_Byte)

# Set Geo Transform
target_ds.SetGeoTransform((x_min, pixel_size, 0, y_max, 0, -pixel_size))

# Write array into raster band, normalize by max, and scale to 1024
target_ds.GetRasterBand(1).WriteArray(np.transpose(yield_grid/np.max(yield_grid))*1024)

# Set Spatial reference and projection
outRasterSRS = osr.SpatialReference()
outRasterSRS.ImportFromEPSG(4326)
target_ds.SetProjection(outRasterSRS.ExportToWkt())

#Flush Cache for raster band
target_ds.GetRasterBand(1).FlushCache()

# Printing raster band to make sure that I'm not crazy
print target_ds.GetRasterBand(1).ReadAsArray()
[[  0   0   0 ...,  39   2   0][  0   0   0 ...,  80  37   0]
 [  0   0   0 ...,  85  32   0]
 ..., 
 [  0  58 119 ...,   0   0   0]
 [  0   0  82 ...,   0   0   0]
 [  0   0   0 ...,   0   0   0]]

The output at the end of the code shows that I am in fact putting values into the raster band, but I'm not sure why the tiff isn't showing any colors.

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I didn't properly close the output target, then this code works... See the answer here

https://gis.stackexchange.com/a/93244/59644

  • This is a common GDAL Python Gotcha - you should avoid FlushCache() and instead deallocate the object by del target_ds or target_ds = None. – Kersten Sep 23 '15 at 6:08

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