def seekimg(self,n=None):
'''Position file to read the nth image.
For now only reads first image ignores n
'''
# the logic involving finding the cursor position
if (n is None):
n = self.recno
if (n < self.beg or n > self.end):
raise IndexError('Error, record out of range')
#print (n, self.recno, self.FID.tell() )
if ((n == self.recno) and (self.imgread==0)):
pass # do nothing
else:
if (n <= self.recno): #ensure cursor less than search pos
self.FID.seek(1024,os.SEEK_SET)
self.dlen =np.fromfile(self.FID,dtype=np.int32,count=1)[0]
self.recno = 0
self.imgread=0
if n == 0:
return
#have to iterate on seeking since dlen varies
#remember for rec recno, cursor is always at recno+1
if(self.imgread==0 ): #move to next header if need to
self.FID.seek(self.dlen*(4+self.byts),os.SEEK_CUR)
for i in range(self.recno+1,n):
#the less seeks performed the faster
#print (i)
self.dlen =np.fromfile(self.FID,dtype=np.int32,count=1)[0]
#print 's',self.dlen
self.FID.seek(self.dlen*(4+self.byts),os.SEEK_CUR)
# we are now at recno in file, read the header and data
#self._clearImage()
self._readHeader()
self.imgread=0
self.recno = n
def seekimg(self, n=None):
'''Position file to read the nth image.
For now only reads first image ignores n
'''
# the logic involving finding the cursor position
if (n is None):
n = self.recno
if (n < self.beg or n > self.end):
raise IndexError('Error, record out of range')
#print (n, self.recno, self.FID.tell() )
if ((n == self.recno) and (self.imgread == 0)):
pass # do nothing
else:
if (n <= self.recno): #ensure cursor less than search pos
self.FID.seek(1024, os.SEEK_SET)
self.dlen = np.fromfile(self.FID, dtype=np.int32, count=1)[0]
self.recno = 0
self.imgread = 0
if n == 0:
return
#have to iterate on seeking since dlen varies
#remember for rec recno, cursor is always at recno+1
if (self.imgread == 0): #move to next header if need to
self.FID.seek(self.dlen * (4 + self.byts), os.SEEK_CUR)
for i in range(self.recno + 1, n):
#the less seeks performed the faster
#print (i)
self.dlen = np.fromfile(self.FID, dtype=np.int32, count=1)[0]
#print 's',self.dlen
self.FID.seek(self.dlen * (4 + self.byts), os.SEEK_CUR)
# we are now at recno in file, read the header and data
#self._clearImage()
self._readHeader()
self.imgread = 0
self.recno = n
def __init__(self, filename, beg, end):
'''Multifile initialization. Open the file.
Here I use the read routine which returns byte objects
(everything is an object in python). I use struct.unpack
to convert the byte object to other data type (int object
etc)
NOTE: At each record n, the file cursor points to record n+1
'''
self.FID = open(filename, "rb")
# self.FID.seek(0,os.SEEK_SET)
self.filename = filename
#br: bytes read
br = self.FID.read(1024)
self.beg = beg
self.end = end
ms_keys = [
'beam_center_x', 'beam_center_y', 'count_time',
'detector_distance', 'frame_time', 'incident_wavelength',
'x_pixel_size', 'y_pixel_size', 'bytes', 'nrows', 'ncols',
'rows_begin', 'rows_end', 'cols_begin', 'cols_end'
]
magic = struct.unpack('@16s', br[:16])
md_temp = struct.unpack('@8d7I916x', br[16:])
self.md = dict(zip(ms_keys, md_temp))
self.imgread = 0
self.recno = 0
# some initialization stuff
self.byts = self.md['bytes']
if (self.byts == 2):
self.valtype = np.uint16
elif (self.byts == 4):
self.valtype = np.uint32
elif (self.byts == 8):
self.valtype = np.float64
#now convert pieces of these bytes to our data
self.dlen = np.fromfile(self.FID, dtype=np.int32, count=1)[0]
def __init__(self,filename,beg,end):
'''Multifile initialization. Open the file.
Here I use the read routine which returns byte objects
(everything is an object in python). I use struct.unpack
to convert the byte object to other data type (int object
etc)
NOTE: At each record n, the file cursor points to record n+1
'''
self.FID = open(filename,"rb")
# self.FID.seek(0,os.SEEK_SET)
self.filename = filename
#br: bytes read
br = self.FID.read(1024)
self.beg=beg
self.end=end
ms_keys = ['beam_center_x', 'beam_center_y', 'count_time', 'detector_distance',
'frame_time', 'incident_wavelength', 'x_pixel_size', 'y_pixel_size',
'bytes',
'nrows', 'ncols', 'rows_begin', 'rows_end', 'cols_begin', 'cols_end'
]
magic = struct.unpack('@16s', br[:16])
md_temp = struct.unpack('@8d7I916x', br[16:])
self.md = dict(zip(ms_keys, md_temp))
self.imgread=0
self.recno = 0
# some initialization stuff
self.byts = self.md['bytes']
if (self.byts==2):
self.valtype = np.uint16
elif (self.byts == 4):
self.valtype = np.uint32
elif (self.byts == 8):
self.valtype = np.float64
#now convert pieces of these bytes to our data
self.dlen =np.fromfile(self.FID,dtype=np.int32,count=1)[0]
def _readImageRaw(self):
p= np.fromfile(self.FID, dtype = np.int32,count= self.dlen)
v= np.fromfile(self.FID, dtype = self.valtype,count= self.dlen)
self.imgread=1
return(p,v)
def _readHeader(self):
self.dlen =np.fromfile(self.FID,dtype=np.int32,count=1)[0]
def _readImageRaw(self):
p = np.fromfile(self.FID, dtype=np.int32, count=self.dlen)
v = np.fromfile(self.FID, dtype=self.valtype, count=self.dlen)
self.imgread = 1
return (p, v)
def _readHeader(self):
self.dlen = np.fromfile(self.FID, dtype=np.int32, count=1)[0]