topic Re: Convert blob/image to Python Image in Python Questions

Convert blob/image to Python Image

KåreMølgaardRasmussen — Tue, 14 May 2024 14:04:56 GMT

Hi Community.

I´m currently working on a script that is able to send an email thru (arc)PY.

I´m using a searhcursor to find the relavant data including blob-data from the _ATTACH table.

But I´m missing a way to convert the blob data to an image (via the PIL framework)

I´ve tried something like this:

with arcpy.da.SearchCursor(_fcAttach,fieldsIn) as imageCursor:

for row in imageCursor:

tmpImg = row[1] #the 'DATA'-field

binary_data = base64.b64decode(tmpImg)

ioData = io.BytesIO(binary_data)

image = Image.open(ioData)

But I get an error like:

PIL.UnidentifiedImageError: cannot identify image file <_io.BytesIO object at 0x0000011D99E7BE50>

Any suggestions or ideas?

Regards

Kåre

Re: Convert blob/image to Python Image

BlakeTerhune — Tue, 14 May 2024 14:17:00 GMT

Sorry, I have not worked with images much, but you could try ImageMagick or wand.

Re: Convert blob/image to Python Image

JakeSkinner — Tue, 14 May 2024 18:07:14 GMT

Hi @KåreMølgaardRasmussen,

The below sample will export the attachments to a directory:

import os, arcpy # Variables tbl = r"C:\Temp\Python\Test.gdb\Graffiti__ATTACH" # Path to attachment table fldBLOB = 'DATA' # Field name of Blob data type field in attachment table fldAttName = 'ATT_NAME' # Field name in attachment table that contains attachment name outFolder = r"C:\Temp\Python\Attachments" # Output folder to export attachments to with arcpy.da.SearchCursor(tbl,[fldBLOB,fldAttName]) as cursor: for row in cursor: binaryRep = row[0] fileName = row[1] # save to disk open(outFolder + os.sep + fileName, 'wb').write(binaryRep.tobytes()) print('Finished')

Re: Convert blob/image to Python Image

BlakeTerhune — Tue, 14 May 2024 18:21:28 GMT

I just noticed the ExportAttachments() function in 3.3. Maybe you could try that too if you're able to upgrade Pro.

Re: Convert blob/image to Python Image

DavidSolari — Thu, 16 May 2024 21:17:55 GMT

Last time I checked, the Data Access Cursor types return BLOB columns as memoryview objects. The docs for PIL's Image.open function say it can open any file-like object that holds binary data. If you're lucky you can just shove the memoryview in there, if not you can do something like:

from io import BytesIO from PIL import Image with arcpy.da.SearchCursor(data, fields) as cur: for row in cur: data = row[index] photo = Image.open(BytesIO(data))

I think the issue with the code above is you're decoding the binary data to base64 which is tripping up PIL, assuming your images were added to an attachment table through the standard ArcGIS methods the data is stored byte for byte without any special encoding.