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