def clip_power(pow,thresh=3):
m = arraystats.mean(pow)
s = arraystats.std(pow)
minval = m-thresh*s*0.5
maxval = m+thresh*s
pow = numpy.clip(pow, minval, maxval)
return pow
def clip_power(pow, thresh=3):
m = arraystats.mean(pow)
s = arraystats.std(pow)
minval = m - thresh * s * 0.5
maxval = m + thresh * s
pow = numpy.clip(pow, minval, maxval)
return pow
def write(a, filename, min=None, max=None, quality=80, newsize=None, stdval=5):
'''
Write a 2-D numpy array to a JPEG file.
Usage:
write(array, filename)
Optional arguments 'min' and 'max' will determine what range of the
input array will be scaled to 0-255 in the jpg file. The default
is to use the following calculation:
min = mean - 3 * stdev
max = mean + 3 * stdev
Optional argument 'quality' is used for jpeg quality, a number between
1 and 100. The default is 80.
Optional argument 'newsize' is used for scaling the image.
'''
## auto determination of range for scaling to 8 bit.
if min is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
min = mean - stdval * std
if max is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
max = mean + stdval * std
## scale to 8 bit
a = numpy.clip(a, min, max)
scale = 255.0 / (max - min)
a = scale * (a - min)
a = a.astype(numpy.uint8)
## use PIL to write JPEG
imsize = a.shape[1], a.shape[0]
nstr = a.tostring()
image = Image.fromstring('L', imsize, nstr, 'raw', 'L', 0, 1)
image.convert('L').save(filename, "JPEG", quality=quality)
if newsize is None:
image.convert('L').save(filename, "JPEG", quality=quality)
else:
image.convert('L').resize(newsize).save(filename,
"JPEG",
quality=quality)
def write(a, filename, min=None, max=None, quality=80, newsize=None):
'''
Write a 2-D numpy array to a JPEG file.
Usage:
write(array, filename)
Optional arguments 'min' and 'max' will determine what range of the
input array will be scaled to 0-255 in the jpg file. The default
is to use the following calculation:
min = mean - 3 * stdev
max = mean + 3 * stdev
Optional argument 'quality' is used for jpeg quality, a number between
1 and 100. The default is 80.
Optional argument 'newsize' is used for scaling the image.
'''
## auto determination of range for scaling to 8 bit.
if min is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
min = mean - 5 * std
if max is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
max = mean + 5 * std
## scale to 8 bit
a = numpy.clip(a, min, max)
scale = 255.0 / (max - min)
a = scale * (a - min)
a = a.astype(numpy.uint8)
## use PIL to write JPEG
imsize = a.shape[1], a.shape[0]
nstr = a.tostring()
image = Image.fromstring('L', imsize, nstr, 'raw', 'L', 0, 1)
image.convert('L').save(filename, "JPEG", quality=quality)
if newsize is None:
image.convert('L').save(filename, "JPEG", quality=quality)
else:
image.convert('L').resize(newsize).save(filename, "JPEG", quality=quality)
def write(a, imfile=None, format=None, limits=None, writefloat=False):
'''
Convert array to 8 bit gray scale and save to filename.
Format is determined from filename extension by PIL.
'''
if limits is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
limits = (mean - 3 * std, mean + 3 * std)
size = a.shape[1], a.shape[0]
if imfile is None:
imfile = sys.stdout
## try saving float data
if writefloat and a.dtype.type in (numpy.int64, numpy.float32):
a = numpy.asarray(a, numpy.float32)
im = Image.frombuffer('F', size, a, 'raw', 'F', 0, 1)
try:
im.save(imfile, format=format)
return
except:
## assume any exception here means that float32 not supported
pass
## save scaled 8 bit data
a = imagefun.linearscale(a, limits, (0, 255))
a = a.clip(0, 255)
a = numpy.asarray(a, numpy.uint8)
im = Image.frombuffer('L', size, a, 'raw', 'L', 0, 1)
try:
im.save(imfile, format=format)
except KeyError:
## bad file format
sys.stderr.write('Bad PIL image format. Try one of these: %s\n' %
(pilformats, ))
def write(a, imfile=None, format=None, limits=None, writefloat=False):
'''
Convert array to 8 bit gray scale and save to filename.
Format is determined from filename extension by PIL.
'''
if limits is None:
mean = arraystats.mean(a)
std = arraystats.std(a)
limits = (mean-3*std, mean+3*std)
size = a.shape[1], a.shape[0]
if imfile is None:
imfile = sys.stdout
## try saving float data
if writefloat and a.dtype.type in (numpy.int64, numpy.float32):
a = numpy.asarray(a, numpy.float32)
im = Image.frombuffer('F', size, a, 'raw', 'F', 0, 1)
try:
im.save(imfile, format=format)
return
except:
## assume any exception here means that float32 not supported
pass
## save scaled 8 bit data
a = imagefun.linearscale(a, limits, (0,255))
a = a.clip(0,255)
a = numpy.asarray(a, numpy.uint8)
im = Image.frombuffer('L', size, a, 'raw', 'L', 0, 1)
try:
im.save(imfile, format=format)
except KeyError:
## bad file format
sys.stderr.write('Bad PIL image format. Try one of these: %s\n' % (pilformats,))