[Image-SIG] manipulate 16 bits Grey matrix

[Jean-Baptiste BUTET]

Hi all,

I have a 1394 cam that has a 16 bit greyscale output.

How can I handle this under PIL ?

Matrix has this shape : [ [  ][  ] [  ]...] and come frome libdc1394
wrapper. 8 bit is well recognise and treated :
---------8 Bits----------

matrix = cam0.current_image
i = Image.fromarray(matrix)

i.save("mypicture.jpg") (or png, or bmp ...)

---------16 bits----------
(code found somewhere)
    matrix = cam0.current_image
    if j ==0 :
        print matrix.size, len(matrix[0]),type(matrix)

    ## 'F' correspond au mode de conversion : F pour Float, bien sûr
## [667,800] est la taille de l'image à créer, dans mon cas

        img = Image.fromstring('F',[480,640], matrix)
        nom = "t"+str(j)+".tif"
        tiff = nom
        fim = open(tiff, 'wb')

## Et conversion en entiers, en précisant le nombre de couleurs...
        img = img.convert('I', colors=65536)

## Sauvegarde au format TIFF. BMP, JPEG, PNG ne sont pas compatibles
## avec le format des données
        img.save(fim, 'tiff')

        fim.close()
----------------------------
---> result
Mode: 640x480_Y16    <- 16 bits OK for cam !
Framerate:  30
307200 640 <class 'pydc1394.camera.Image'>   <-  lenght of string, width
Traceback (most recent call last):
  File "16save_image.py", line 78, in <module>
    img = Image.fromstring('F',[481,641], matrix)
  File "/usr/lib/python2.7/site-packages/PIL/Image.py", line 1797, in fromstring
    im.fromstring(data, decoder_name, args)
  File "/usr/lib/python2.7/site-packages/PIL/Image.py", line 594, in fromstring
    raise ValueError("not enough image data")
ValueError: not enough image data


I really don't see what the problem...

Thanks for response.

JB