#
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# The Python Imaging Library.
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#
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# SPIDER image file handling
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#
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# History:
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# 2004-08-02 Created BB
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# 2006-03-02 added save method
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# 2006-03-13 added support for stack images
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#
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# Copyright (c) 2004 by Health Research Inc. (HRI) RENSSELAER, NY 12144.
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# Copyright (c) 2004 by William Baxter.
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# Copyright (c) 2004 by Secret Labs AB.
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# Copyright (c) 2004 by Fredrik Lundh.
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#
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##
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# Image plugin for the Spider image format. This format is is used
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# by the SPIDER software, in processing image data from electron
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# microscopy and tomography.
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##
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#
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# SpiderImagePlugin.py
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#
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# The Spider image format is used by SPIDER software, in processing
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# image data from electron microscopy and tomography.
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#
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# Spider home page:
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# http://www.wadsworth.org/spider_doc/spider/docs/spider.html
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#
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# Details about the Spider image format:
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# http://www.wadsworth.org/spider_doc/spider/docs/image_doc.html
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#
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import Image, ImageFile
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import os, struct, sys
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def isInt(f):
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try:
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i = int(f)
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if f-i == 0: return 1
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else: return 0
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except:
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return 0
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iforms = [1,3,-11,-12,-21,-22]
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# There is no magic number to identify Spider files, so just check a
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# series of header locations to see if they have reasonable values.
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# Returns no.of bytes in the header, if it is a valid Spider header,
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# otherwise returns 0
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def isSpiderHeader(t):
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h = (99,) + t # add 1 value so can use spider header index start=1
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# header values 1,2,5,12,13,22,23 should be integers
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for i in [1,2,5,12,13,22,23]:
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if not isInt(h[i]): return 0
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# check iform
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iform = int(h[5])
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if not iform in iforms: return 0
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# check other header values
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labrec = int(h[13]) # no. records in file header
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labbyt = int(h[22]) # total no. of bytes in header
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lenbyt = int(h[23]) # record length in bytes
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#print "labrec = %d, labbyt = %d, lenbyt = %d" % (labrec,labbyt,lenbyt)
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if labbyt != (labrec * lenbyt): return 0
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# looks like a valid header
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return labbyt
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def isSpiderImage(filename):
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fp = open(filename,'rb')
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f = fp.read(92) # read 23 * 4 bytes
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fp.close()
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bigendian = 1
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t = struct.unpack('>23f',f) # try big-endian first
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hdrlen = isSpiderHeader(t)
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if hdrlen == 0:
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bigendian = 0
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t = struct.unpack('<23f',f) # little-endian
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hdrlen = isSpiderHeader(t)
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return hdrlen
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class SpiderImageFile(ImageFile.ImageFile):
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format = "SPIDER"
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format_description = "Spider 2D image"
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def _open(self):
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# check header
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n = 27 * 4 # read 27 float values
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f = self.fp.read(n)
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try:
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self.bigendian = 1
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t = struct.unpack('>27f',f) # try big-endian first
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hdrlen = isSpiderHeader(t)
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if hdrlen == 0:
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self.bigendian = 0
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t = struct.unpack('<27f',f) # little-endian
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hdrlen = isSpiderHeader(t)
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if hdrlen == 0:
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raise SyntaxError, "not a valid Spider file"
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except struct.error:
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raise SyntaxError, "not a valid Spider file"
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h = (99,) + t # add 1 value : spider header index starts at 1
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iform = int(h[5])
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if iform != 1:
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raise SyntaxError, "not a Spider 2D image"
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self.size = int(h[12]), int(h[2]) # size in pixels (width, height)
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self.istack = int(h[24])
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self.imgnumber = int(h[27])
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if self.istack == 0 and self.imgnumber == 0:
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# stk=0, img=0: a regular 2D image
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offset = hdrlen
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self.nimages = 1
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elif self.istack > 0 and self.imgnumber == 0:
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# stk>0, img=0: Opening the stack for the first time
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self.imgbytes = int(h[12]) * int(h[2]) * 4
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self.hdrlen = hdrlen
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self.nimages = int(h[26])
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# Point to the first image in the stack
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offset = hdrlen * 2
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self.imgnumber = 1
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elif self.istack == 0 and self.imgnumber > 0:
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# stk=0, img>0: an image within the stack
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offset = hdrlen + self.stkoffset
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self.istack = 2 # So Image knows it's still a stack
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else:
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raise SyntaxError, "inconsistent stack header values"
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if self.bigendian:
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self.rawmode = "F;32BF"
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else:
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self.rawmode = "F;32F"
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self.mode = "F"
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self.tile = [("raw", (0, 0) + self.size, offset,
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(self.rawmode, 0, 1))]
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self.__fp = self.fp # FIXME: hack
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# 1st image index is zero (although SPIDER imgnumber starts at 1)
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def tell(self):
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if self.imgnumber < 1:
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return 0
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else:
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return self.imgnumber - 1
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def seek(self, frame):
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if self.istack == 0:
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return
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if frame >= self.nimages:
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raise EOFError, "attempt to seek past end of file"
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self.stkoffset = self.hdrlen + frame * (self.hdrlen + self.imgbytes)
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self.fp = self.__fp
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self.fp.seek(self.stkoffset)
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self._open()
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# returns a byte image after rescaling to 0..255
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def convert2byte(self, depth=255):
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(min, max) = self.getextrema()
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m = 1
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if max != min:
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m = depth / (max-min)
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b = -m * min
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return self.point(lambda i, m=m, b=b: i * m + b).convert("L")
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# returns a ImageTk.PhotoImage object, after rescaling to 0..255
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def tkPhotoImage(self):
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import ImageTk
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return ImageTk.PhotoImage(self.convert2byte(), palette=256)
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# --------------------------------------------------------------------
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# Image series
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# given a list of filenames, return a list of images
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def loadImageSeries(filelist=None):
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" create a list of Image.images for use in montage "
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if filelist == None or len(filelist) < 1:
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return
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imglist = []
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for img in filelist:
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if not os.path.exists(img):
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print "unable to find %s" % img
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continue
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try:
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im = Image.open(img).convert2byte()
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except:
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if not isSpiderImage(img):
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print img + " is not a Spider image file"
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continue
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im.info['filename'] = img
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imglist.append(im)
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return imglist
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# --------------------------------------------------------------------
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# For saving images in Spider format
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def makeSpiderHeader(im):
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nsam,nrow = im.size
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lenbyt = nsam * 4 # There are labrec records in the header
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labrec = 1024 / lenbyt
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if 1024%lenbyt != 0: labrec += 1
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labbyt = labrec * lenbyt
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hdr = []
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nvalues = labbyt / 4
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for i in range(nvalues):
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hdr.append(0.0)
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if len(hdr) < 23:
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return []
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# NB these are Fortran indices
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hdr[1] = 1.0 # nslice (=1 for an image)
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hdr[2] = float(nrow) # number of rows per slice
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hdr[5] = 1.0 # iform for 2D image
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hdr[12] = float(nsam) # number of pixels per line
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hdr[13] = float(labrec) # number of records in file header
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hdr[22] = float(labbyt) # total number of bytes in header
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hdr[23] = float(lenbyt) # record length in bytes
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# adjust for Fortran indexing
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hdr = hdr[1:]
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hdr.append(0.0)
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# pack binary data into a string
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hdrstr = []
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for v in hdr:
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hdrstr.append(struct.pack('f',v))
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return hdrstr
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def _save(im, fp, filename):
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if im.mode[0] != "F":
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im = im.convert('F')
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hdr = makeSpiderHeader(im)
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if len(hdr) < 256:
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raise IOError, "Error creating Spider header"
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# write the SPIDER header
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try:
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fp = open(filename, 'wb')
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except:
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raise IOError, "Unable to open %s for writing" % filename
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fp.writelines(hdr)
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rawmode = "F;32NF" #32-bit native floating point
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ImageFile._save(im, fp, [("raw", (0,0)+im.size, 0, (rawmode,0,1))])
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fp.close()
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def _save_spider(im, fp, filename):
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# get the filename extension and register it with Image
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fn, ext = os.path.splitext(filename)
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Image.register_extension("SPIDER", ext)
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_save(im, fp, filename)
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# --------------------------------------------------------------------
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Image.register_open("SPIDER", SpiderImageFile)
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Image.register_save("SPIDER", _save_spider)
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if __name__ == "__main__":
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if not sys.argv[1:]:
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print "Syntax: python SpiderImagePlugin.py Spiderimage [outfile]"
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sys.exit()
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filename = sys.argv[1]
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if not isSpiderImage(filename):
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print "input image must be in Spider format"
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sys.exit()
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outfile = ""
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if len(sys.argv[1:]) > 1:
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outfile = sys.argv[2]
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im = Image.open(filename)
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print "image: " + str(im)
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print "format: " + str(im.format)
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print "size: " + str(im.size)
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print "mode: " + str(im.mode)
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print "max, min: ",
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print im.getextrema()
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if outfile != "":
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# perform some image operation
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im = im.transpose(Image.FLIP_LEFT_RIGHT)
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print "saving a flipped version of %s as %s " % (os.path.basename(filename), outfile)
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im.save(outfile, "SPIDER")
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