David Haberthür
b7ed22991c
The Python example now features reading and displaying an example DMP file. The example.DMP file will be added to the repository once I get the clearance from the original user. Additionally we load a "random" image from the web and save that as DMP to show how to save images as DMP. Also renamed script :)
75 lines
2.3 KiB
Python
75 lines
2.3 KiB
Python
#! /usr/bin/env python
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# -*- coding: utf-8 -*-
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"""
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Python script to read DMP file.
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Written by David Haberthür <david.haberthuer@psi.ch> based on an initial
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version by Martin Nyvlt <martin.nyvlt@gmail.com>
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"""
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import numpy
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import os
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import matplotlib.pyplot as plt
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import urllib2
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def readDMP(filename):
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"""
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Opens and reads DMP file.
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Returns a numpy ndarray which can be displayed/written/handled further.
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"""
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# Open the file
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dmpfile = open(filename, 'rb')
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# The DMP file format is a very simple file format; the header consists of
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# 3 unsigned 16bit integers specifying the image dimensions, followed by a
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# stream of 32-bit floats in little-endian byte order.
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# Load Header. It's first two values are the image size.
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header = numpy.fromfile(dmpfile, numpy.int16, 3)
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imageSize = (header[1], header[0])
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# Load file and reshape to the size from the header
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image = numpy.fromfile(dmpfile, numpy.float32)
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image = image.reshape(imageSize)
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dmpfile.close()
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return image
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def writeDMP(array, outputfilename):
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"""
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Writes numpy ndarray to DMP file.
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The array.dtype should be numpy.float32.
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If it's not, it will be converted before saving.
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"""
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# Open the file for writing (binary)
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dmpfile = open(outputfilename, 'wb')
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# Create header. *Must* be dtype numpy.uint16!
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width = numpy.array(array.shape[1])
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height = numpy.array(array.shape[0])
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header = numpy.array([width, height, 0], numpy.uint16)
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header.tofile(dmpfile)
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# Write Image data. dtype has to be np.float32
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if array.dtype != 'float32':
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array = array.astype(numpy.float32)
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array.tofile(dmpfile)
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dmpfile.close()
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# Read example DMP file with the function defined above
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DMPFileName = os.path.join(os.getcwd(), '..', 'example.DMP')
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DMP = readDMP(DMPFileName)
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# Show example image
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plt.subplot(121)
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plt.imshow(DMP, cmap='gray')
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plt.title('example.DMP')
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# Load some image from the internet and save its green channel as DMP.
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URL = urllib2.urlopen('http://www.psi.ch/sls/tomcat/HomeEN/tomcat_banner.png')
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image = plt.imread(URL)[:, :, 1]
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writeDMP(image, 'randomimage.DMP')
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# Read the image again as DMP and display it
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plt.subplot(122)
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plt.imshow(readDMP('randomimage.DMP'), cmap='gray')
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plt.title('Some random image')
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plt.show()
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print 'Now open randomimage.DMP in Fiji!'
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