em2d.py

"""@namespace IMP.pmi.restraints.em2d
Restraints for handling electron microscopy images.
"""

from __future__ import print_function
import IMP
import IMP.core
import IMP.algebra
import IMP.atom
import IMP.pmi.tools


class ElectronMicroscopy2D(object):
    """Fit particles against a set of class averages by principal components.
    Compares how well the principal components of the segmented class
    average fit to the principal components of the particles.
    """
    def __init__(self,
                 representation=None,
                 images=None,
                 pixel_size=None,
                 image_resolution=None,
                 projection_number=None,
                 resolution=None,
                 n_components=1,
                 hier=None):
        """Constructor.
        @param representation DEPRECATED, pass 'hier' instead
        @param images 2D class average filenames in PGM text format
        @param pixel_size Pixel size in angstroms
        @param image_resolution Estimated resolution of the images
               in angstroms
        @param projection_number Number of projections of the model
               to generate and fit to images. The lower the number, the
               faster the evaluation, but the lower the accuracy
        @param resolution Which level of
               [model representation](@ref pmi_resolution) to use in the fit
        @param n_components Number of the largest components to be
               considered for the EM image
        @param hier The root hierarchy for applying the restraint
        """

        import IMP.em2d

        # check input
        if images is None:
            raise Exception("Must pass images")
        if pixel_size is None:
            raise Exception("Must pass pixel size")
        if image_resolution is None:
            raise Exception("must pass image resolution")

        # PMI1/2 selection
        if representation is None and hier is not None:
            self.m = hier.get_model()
            particles = IMP.atom.Selection(hier,resolution=resolution).get_selected_particles()
        elif hier is None and representation is not None:
            self.m = representation.prot.get_model()
            particles = IMP.pmi.tools.select(
                representation,
                resolution=resolution)
        else:
            raise Exception("EM2D: must pass hier or representation")
        self.weight = 1.0
        self.rs = IMP.RestraintSet(self.m, 'em2d')
        self.label = "None"

        # read PGM FORMAT images
        # format conversion recommendataion - first run "e2proc2d.py $FILE ${NEW_FILE}.pgm"
        # then, run "convert ${NEW_FILE}.pgm -compress none ${NEW_FILE2}.pgm"
        if (n_components >= 2) :    # Number of the largest components to be considered for the EM image
            em2d = IMP.em2d.PCAFitRestraint(
                particles, images, pixel_size, image_resolution, projection_number, True, n_components)
        else :
            em2d = IMP.em2d.PCAFitRestraint(
                particles, images, pixel_size, image_resolution, projection_number, True)
        self.rs.add_restraint(em2d)

    def set_label(self, label):
        self.label = label

    def add_to_model(self):
        IMP.pmi.tools.add_restraint_to_model(self.m, self.rs)

    def get_restraint(self):
        return self.rs

    def set_weight(self,weight):
        self.weight = weight
        self.rs.set_weight(self.weight)

    def get_output(self):
        self.m.update()
        output = {}
        score = self.weight*self.rs.unprotected_evaluate(None)
        output["_TotalScore"] = str(score)
        output["ElectronMicroscopy2D_" + self.label] = str(score)
        return output

class ElectronMicroscopy2D_FFT():
    """FFT based image alignment, developed by Javier Velazquez-Muriel"""
    def __init__(
            self,
            representation=None,
            images=None,
            pixel_size=None,
            image_resolution=None,
            projection_number=None,
            resolution=None,
            hier=None):
        """Constructor.
        @param representation DEPRECATED, pass 'hier' instead
        @param images SPIDER FORMAT images (format conversion should be done through EM2EM)
        @param pixel_size sampling rate of the available EM images (angstroms)
        @param image_resolution resolution at which you want to generate the projections of the model
               In principle you want "perfect" projections, so use the highest resolution
        @param projection_number Number of projections of the model (coarse registration) to
               estimate the registration parameters
        @param resolution Which level of
               [model representation](@ref pmi_resolution) to use in the fit
        @param n_components Number of the largest components to be
               considered for the EM image
        @param hier The root hierarchy for applying the restraint
        """

        import IMP.em2d

        # check input
        if images is None:
            raise Exception("EM2D_FFT: must pass images")
        if pixel_size is None:
            raise Exception("EM2D_FFT: must pass pixel size")
        if image_resolution is None:
            raise Exception("EM2D_FFT: must pass image resolution")
        if projection_number is None:
            raise Exception("EM2D_FFT: must pass projection_number")

        # PMI1/2 selection
        if representation is None and hier is not None:
            self.m = hier.get_model()
            particles = IMP.atom.Selection(hier,resolution=resolution).get_selected_particles()
        elif hier is None and representation is not None:
            self.m = representation.prot.get_model()
            particles = IMP.pmi.tools.select(
                representation,
                resolution=resolution)
        else:
            raise Exception("EM2D: must pass hier or representation")

        self.weight=1.0
        self.rs = IMP.RestraintSet(self.m, 'em2d_FFT')
        self.label = "None"

        # read
        srw = IMP.em2d.SpiderImageReaderWriter()
        imgs = IMP.em2d.read_images(images, srw)
        rows = imgs[0].get_header().get_number_of_rows()
        cols = imgs[0].get_header().get_number_of_columns()

        params = IMP.em2d.Em2DRestraintParameters(pixel_size, image_resolution, projection_number)

        # This method (recommended) uses preprocessing of the images and projections to speed-up the registration
        params.coarse_registration_method = IMP.em2d.ALIGN2D_PREPROCESSING
        params.optimization_steps = 50
        params.simplex_initial_length = 0.1
        params.simplex_minimum_size = 0.02

        # use true if you want to save the projections from the model that best match the EM images
        params.save_match_images = False

        ######################
        # set up the em2D restraint
        ######################
        score_function = IMP.em2d.EM2DScore()
        em2d_restraint = IMP.em2d.Em2DRestraint(self.m)
        em2d_restraint.setup(score_function, params)
        em2d_restraint.set_images(imgs)
        em2d_restraint.set_fast_mode(5)
        em2d_restraint.set_name("em2d_restraint")

        print ("len(particles) = ", len(particles))
        container = IMP.container.ListSingletonContainer(self.m, particles)
        em2d_restraint.set_particles(container)

        self.rs.add_restraint(em2d_restraint)

    def set_label(self, label):
        self.label = label

    def add_to_model(self):
        IMP.pmi.tools.add_restraint_to_model(self.m, self.rs)

    def get_restraint(self):
        return self.rs

    def set_weight(self,weight):
        self.weight=weight
        self.rs.set_weight(self.weight)

    def get_output(self):
        self.m.update()
        output = {}
        score = self.weight*self.rs.unprotected_evaluate(None)
        output["_TotalScore"] = str(score)
        output["ElectronMicroscopy2D_FFT_" + self.label] = str(score)
        return output