image_handling.py 文件源码

def plot_channel(image, name, cmap='gist_heat', log=True, dex=3, zero_factor=1.0e-10, 
                 label=None, label_color='w', label_size='large'):
    """
    This function will plot a single channel. *image* is an array shaped like
    (N,M), *name* is the pefix for the output filename.  *cmap* is the name of
    the colormap to apply, *log* is whether or not the channel should be
    logged.  Additionally, you may optionally specify the minimum-value cutoff
    for scaling as *dex*, which is taken with respect to the minimum value of
    the image.  *zero_factor* applies a minimum value to all zero-valued
    elements.  Optionally, *label*, *label_color* and *label_size* may be
    specified.
    """
    import matplotlib
    import pylab
    Nvec = image.shape[0]
    image[np.isnan(image)] = 0.0
    ma = image[image>0.0].max()
    image[image==0.0] = ma*zero_factor
    if log:
        mynorm = matplotlib.colors.LogNorm(ma/(10.**dex), ma)

    pylab.clf()
    pylab.gcf().set_dpi(100)
    pylab.gcf().set_size_inches((Nvec/100.0, Nvec/100.0))
    pylab.gcf().subplots_adjust(left=0.0, right=1.0, bottom=0.0, top=1.0, wspace=0.0, hspace=0.0)
    mycm = pylab.cm.get_cmap(cmap)
    if log:
        pylab.imshow(image,cmap=mycm, norm=mynorm, interpolation='nearest')
    else:
        pylab.imshow(image,cmap=mycm, interpolation='nearest')
    if label is not None:
        pylab.text(20, 20,label, color = label_color, size=label_size) 
    pylab.savefig("%s_%s.png" % (name,cmap))
    pylab.clf()