[mmset2mat] [Up] [mmcmp] Image file I/O

mmreadgray
Read an image from a commercial file format and stores it as a gray-scale image.

Synopsis

y = mmreadgray( filename )

Implemented in Python.

Input

filename

String

Name of file to read.

Output

y	Image Gray-scale (uint8 or uint16) or binary image.

Description

mmreadgray reads the image in filename and stores it in y, an uint8 gray-scale image (without colormap). If the input file is a color RGB image, it is converted to gray-scale using the equation: y = 0.2989 R + 0.587 G + 0.114 B. This functions uses de PIL module.

Examples

>>> a=mmreadgray('cookies.tif')

>>> mmshow(a)


a

Source Code
        def mmreadgray(filename):
    import adpil
    import Numeric
    y = adpil.adread(filename)
    if (len(y.shape) == 3) and (y.shape[0] == 3):
       if Numeric.alltrue(Numeric.alltrue(y[0,:,:] == y[1,:,:] and
                                          y[0,:,:] == y[2,:,:])):
          y = y[0,:,:]
       else:
          print 'Warning: converting true-color RGB image to gray'
          y = mmubyte(0.2989 * y[0,:,:] + 
                      0.5870 * y[1,:,:] + 
                      0.1140 * y[2,:,:])
    elif (len(y.shape) == 2):
       pass
    else:
       raise ValueError, 'Error, it is not 2D image'
    return y
    
      

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Copyright (c) 2003, Roberto A. Lotufo, UNICAMP-University of Campinas; Rubens C. Machado, CenPRA-Renato Archer Research Center.

mmreadgray Read an image from a commercial file format and stores it as a gray-scale image.