Open a multichannel image in Python OpenCV2

Question

I have a 4 band multichannel image (TIF) which is an unsigned 16 bit image. I am using the following:

    opencv2 
    python

I have done the following at the beginning of my code

    import cv2

When I use

  i = cv2.imread('img.tif')

it is reading all the four bands but as UINT8. When I use

  i = cv2.imread('img.tif', cv2.CV_16U)

it reads only one channel of the image. What should be done to read all the four channels in 16bit unsigned?

Aurelius · Accepted Answer · 2013-07-08 20:02:48Z

1

Try passing the flag cv2.IMREAD_ANYDEPTH. The documentation states this flag will:

If set, return 16-bit/32-bit image when the input has the corresponding depth, otherwise convert it to 8-bit.

i = cv2.imread('img.tif', flags=cv2.IMREAD_ANYDEPTH)

If that doesn't work, try the cv2.IMREAD_UNCHANGED flag instead. It's not documented, but it looks like it may also work.

answered Jul 8, 2013 at 20:02

Aurelius

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3 Comments

Nope this does not work. My image loads but only one channel! I have cross verfied this with Matlab where my image loads as UINT16 / 4 channel.

It appears that GDAL from osgeo works better in terms of reading images.

@Indian Did you try the IMREAD_UNCHANGED flag? It works for me.