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eman2:metadata

Parameters/Metadata stored in EMData Objects

The EMData object, and its representation on disk in the BDB local database, XML files, and when serialized in Python using 'pickle', supports the concept of arbitrary header parameters also known as metadata. This metadata are key/value pairs. The keys are always simple ascii text, and the values may be virtually anything represented as an EMObject, including simple ints, floats and strings, as well as more complicated objects such as Transform classes. If an EMData object is stored in some fashion other than the 3 mechanisms above, some loss of metadata is almost guaranteed. The file i/o objects will try to preserve some of the basic metadata, but most of the cryoEM formats simply don't support arbitrary header-data. The EMAN2 convention is to use BDB for most internal purposes, and to use HDF5 for data transfer/exchange.

This page will serve as a repository for the officially supported parameter key/value pairs. While you are free to set any metadata keys/values you like in an EMData object, the names listed here may be interpreted in specific ways by specific modules within EMAN, so it would be unwise to abuse them. Also, if you make up your own name for some purpose, it wouldn't hurt to register it here in the 'unofficial' section, to avoid it being used by someone else for a different purpose.

Native HDF5 Image Compression

EMAN2 supports lossless and lossy (through bit reduction) compression via native HDF5 mechanisms. To write an image with compression, the storage mode must be EM_COMPRESSED. render_bits, render_min and render_max should also be set (otherwise lossless compression in floating point mode will take place, which won't save much space. These parameters are not stored under these names in the file). render_compress_level may optionally be set (no quality impact, just speed/size tradeoff). Upon storage, the parameters: stored_rendermin, stored_rendermax and stored_renderbits will be set, and when the file is read from disk, the values will be rescaled to match the original image, to within the limits permitted by render_bits.

Special tags (read-only for getting image info)

These values are cached and only recomputed if the image changes

TagTypeDescription
nx,ny,nz int Dimensions of the image, also available as get_xsize(),etc. Note: Assignments such as e[“nx”] = 30 are an (not preferred) alternative to set_size(nx,ny,nz)
minimum float Smallest value in the image
maximum float Largest value in the image
mean float The average pixel value in the image
sigma float The standard deviation of the pixel values in the image
square_sum float Sum of the squares of the pixel values
mean_nonzero float The mean value of all nonzero pixels
sigma_nonzero float The standard deviation of the pixels ignoring pixels which are zero
all_intintTrue if all values in the image are integers, otherwise false

These values are computed only when requested, they are not part of get_attr_dict()

TagTypeDescription
skewness float Skewness of the pixel values
kurtosis float Kurtosis of the pixel values
median float Median value of the pixel values
nonzero_median float Median value of nonzero pixels
moment_inertiafloatMoment of inertia about the image center, considering only positive pixel values
radius_gyrationfloatRadius of gyration about the image center, considering only positive pixel values

Official tags (used in EMAN2/SPARX as distributed):

TagTypeDescription
apix_x,y,z float Angstroms per pixel on the x-axis (also _y and _z). If _y or _z are 0 or not present it will be assumed that they are the same as _x. Note that CTF objects have an independent value for A/pix
changecount int An integer which is incremented every time the image is marked as changed
class_id int Set by classification routines to indicate which class number the particle is in
class_ptcl_src string In a class-average, this is the file containing the raw images used to create the average
class_ptcl_idxs tuple In a class-average, this is a list of particle numbers used in the final average (see class_ptcl_src and exc_class_ptcl_idxs)
class_ptcl_qual tuple In a class-average, this is the mean quality of the particles vs the average
class_ptcl_qual_sigma tuple In a class-average, this is the standard deviation of the quality of the particles vs the average
class_qual float The similarity of the class-average to the alignment reference (usually a projection). As usual, smaller is better
class_ssnrfloat listSSNR computed from the FSC between the class-average and a reference. N points equivalent to the radius(+1) of the particle
ctf Ctf subclass A subclass of Ctf containing all CTF parameters
ctf_phase_flipped bool Set to true if the CTF phases have been flipped
ctf_wiener_filtered bool Set to true if a Wiener filter has been applied
ctf_snr_total float list Set in class-averages by some averagers indicating the total estimated radial SNR of the average
data_path string Used for virtual stacks. References binary file and location for image data as file*location
data_source string Used in virtual stacks. This is a reference back to the source image from which this image was derived
data_n int Used in virtual stacks. This is the image number
datatype int Number format used when storing the file to disk, see format-specific parameters below for formats supported by each file. 0:EM_UNKNOWN, 1:EM_CHAR, 2:EM_UCHAR, 3:EM_SHORT, 4:EM_USHORT, 5:EM_INT, 6:EM_UINT, 7:EM_FLOAT, 8:EM_DOUBLE, 9:EM_SHORT_COMPLEX, 10:EM_USHORT_COMPLEX, 11:EM_FLOAT_COMPLEX,12:EM_COMPRESSED
eigval float Eigenvalue, only set for images which represent Eigenvectors
eval_contrast_lowres float Low-resoluton contrsast in the image (mean power from 25-200 A / mean power >20 A)
exc_class_ptcl_idxs tuple In a class-average, this is a list of particle numbers provided to the averager, but excluded from the final average (see class_ptcl_src)
filter_curve float list Returned by some processors. List of floats representing an applied radial Fourier filter
hadzeroedge int If set, indicates that the mask.zeroedgefill processor detected an edge in need of filling
hostendian str Endianness of the computer in use. “big” or “little”
imageendian str Endianness of the image. “big” or “little”. Only set for image files where this is an important distinction.
is_complex int Flag indicating that the image is complex (R/I or A/P pairs)
is_complex_ri int Flag indicating that a complex image is R/I not A/P
lst_comment string When a file is read from LSX format, any comment present will be stored here
match_n int used to represent the number of a reference particle this particle best matched
match_qual float used to represent the quality associated with match_n, smaller is a better match
microscope_voltage float Voltage of the microscope in kV
microscope_cs float Cs of the microscope in mm
model_id int in a projection during multi-model refinement, this is the index of the model for the current projection. For single model refinements always 1. In EMAN2.0x the first model was number 0, in EMAN2.1x the first model is number 1.
movie_frames int If this is one particle from a direct detector movie, this is the total number of frames in the movie
movie_n int If this is one particle from a direct detector movie, this is the sequence number within the movie (0 is the first frame as ususal)
movie_cc float list Correlation for each frame in a particle movie
movie_tx float list X translation for each frame in a particle movie
movie_ty float list Y translation for each frame in a particle movie
norm_mult float When images are normalized there is a linear transformation. This is the multiplicative component (happens first). Only some processors provide it.
norm_add float When images are normalized there is a linear transformation. This is the additive component for processors that provide it.
projection_image string In a class-average, this represents the image file which was used for initial alignment references
projection_image_idx string In a class-average, this represents the specific image number in projection_image
ptcl_repr int If an image/volume represents the combination of one or more other images, this is the count of the number of particles that went into the average
ptcl_helix_coords tuple The two endpoints and a box width that defines a helix box (x1, y1, x2, y2, box_width)
ptcl_source_coord tuple The central coordinate of a boxed particle in terms of its source image, normally (x,y), may be (x,y,z) for subtomograms
ptcl_source_image string The name of the image from which the particle was extracted. Full path, may be in bdb syntax
reconstruct_norm float Normalization factor applied to a single projection/class-average during reconstruction
reconstruct_qual float Quality of a single projection/class-average relative to others during reconstruction. Unlike with comparators, larger values are better.
reconstruct_preproc bool Set if the image has been preprocessed for use with a reconstructor
render_min,max float Used when rendering an image to integer formats. These are the values representing the minimum and maximum integer values. These values are never written to a file, but are set prior to saving. see stored_rendermin
render_bitsintSpecify the number of bits to keep in integer representation of the data. Bit reduction is lossy, but will not save disk space unless saving with compression enabled. Special value -1 can be used to specify floating point for lossless compression. This is never stored in a file. See stored_renderbits
render_compress_levelintSpecify the compression level to use when writing compressed HDF files. Default is 1, which provides decent compression quickly. Valid range is 1-9. This value will be stored if set.
score_alignfloatScore associated with xform.align2d or xform.align3d. Meaning varies with alignment algorithm, but smaller should be better. Not all alignment routines return this.
segment_centers float list Used when a volume has been segmented into regions. Set of 3*nregions floats in x1,y1,z1,x2,y2,z2,… order, indicating the center of each region as defined by the specific algorithm
sigma_presub float The sigma of the input image prior to reference subtraction, optionally returned by math.sub.optimal processor
source_orig_path string When an image is copied from one file to another, this can be used to reference its original location
source_orig_n string When an image is copied from one file to another, this can be used to reference its original number within the file
source_path string When an image is read from a file, this is set to the filename
source_n string When an image is read from a file, this is set to the image number (first image is 0)
stored_renderminfloat When an image has been stored in integer mode, this value is used to restore the original floating point range when reading. Any value set for this property prior to saving will be ignored and overwritten. To set this value prior to saving, see render_min.
stored_rendermaxfloat When an image has been stored in integer mode, this value is used to restore the original floating point range when reading. Any value set for this property prior to saving will be ignored and overwritten. To set this value prior to saving, see render_max.
stored_renderbitsfloat The number of bits used when saving this file. Special value -1 can be used to specify floating point for lossless compression. To set this value prior to saving, see render_bits.
stored_truncatedintNumber of pixels with truncated values when saving with rendermin and rendermax
subvolume_x0,y0,z0 int Used when the EMData stores only a portion of a larger image in certain contexts (notably direct Fourier inversion. This represents the location of the origin of 'this' in the larger virtual volume
subvolume_full_nx,ny,nz int Used with subvolume_x0,… Specifies the size of the virtual volume that 'this' is a part of
threed_ptcl_src string In a 3-D map, this is the file containing the raw images used to create the reconstruction
threed_ptcl_idxs tuple In a 3-D map, this is a list of particle numbers used in the final reconstruction (see threed_ptcl_src)
threed_excl_ptcl_idxs tuple In a 3-D map, this is a list of particle numbers excluded from the final map (see threed_ptcl_src)
tilt_angle floatTilt angle of a specific image in a tilt series, derived from recording software
tilt_defocus_est floatEstimated defocus of a tilt in a tilt series from recording software
tilt_dose floatDose in a single tilt in a tilt series
tilt_dose_begin floatDose expended in the tilt series at the beginning of a specific tilt image
tilt_seq intRecorded sequence number of a single tilt in a tilt series, starting with 0
timestamp string When data for an image is being written this is updated with the current time. It is not updated for metadata changes, only when the image data is written
symxform Transform A Transform object produced by e2symsearch.py
xform.projection Transform A Transform object used by Projectors. It is applied to a 3-D model prior to projecting by summing along Z. The inverse of this Transform is used by Reconstructors
xform.align2d Transform A Transform object representing a 2-D transformation used to align this EMData object to a reference in 2-D
xform.align3d Transform A Transform object representing a 3-D transformation used to align this (3-D) EMData object to a (3-D) reference

Proposed new Official tags (comments welcome):

TagTypeDescriptionComments
apix_scan float Scan pixel size in Angstroms (there are already parameters for apix_x/y/z above. Is this different in some way ?, you could provide this as supplementary information, but apix_x/y/z remain the 'official' values. Is this what you want ?)
box_location int_array 4 values, x0, y0, xsize, ysize representing the location of the particle in the original (box_source) image (Pawel suggested this be changed to the reduced image, because normally we first reduce the micrograph, the window it.) (No, the box location should be in the coordinates of the referenced 'parent' image. If you want to reference a reduced image you can, but I think it makes a lot more sense to provide the capability of refining the coordinates from the reduced image when you return to the original image.) Pawel: the coordinates in boxer refer to the image from windowing was done. This is is (or can be) a reduced micrograph. There is more confusion here: name apix_scan suggests this is pixel size of the scan, NOT THE REDUCED MICROGRAPH FROM WHICH PARTICLES WERE WINDOWED. Incidentally, both pixel sizes are needed and have to be in the header. Steve: This differs from the philosophy of e2boxer, which is that you always provide e2boxer with the original image, it may internally downscale it for boxing, but the final box positions are in terms of the original image. I don't understand why you would want to externally downscale, then have to rescale the coordinates again later ? This is very messy. Anyway, any single image has a particluar A/pix value associated with it. I have no objections to something like apix_original, but what exactly is the point ? You aren't likely to rescale reduced images back to their original size…
box_score float A value representing the relative quality (meaning may vary) of this particle compared to others
box_source string Filename (not full path) of the image this particle was extracted from
box_source_id string Other (database) identifier of the image the raw data came from if available

Unofficial tags (To prevent reuse, used by someone in their own code or for testing):

Tags used to store header information derived from other file formats:

Parameters from MRC file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_UCHAR, EM_SHORT, EM_USHORT, EM_SHORT_COMPLEX, EM_FLOAT, EM_FLOAT_COMPLEX
apix_x,y,z float Angstroms per pixel on the x-axis (also _y and _z). If _y or _z are 0 or not present it will be assumed that they are the same as _x. Note that CTF objects have an independent value for A/pix
MRC.minimum float Minimum density value
MRC.maximum float Maximum density value
MRC.mean float Mean density value
origin_x, y, z float image origin for x, y, z axis
MRC.nxstart int No. of first column in map
MRC.nystart int No. of first row in map
MRC.nzstart int No. of first section in map
MRC.mx int Number of intervals along X
MRC.my int Number of intervals along Y
MRC.mz int Number of intervals along Z
MRC.nx int number of columns
MRC.ny int number of rows
MRC.nz int number of sections
MRC.xlen float Cell dimensions (Angstroms)
MRC.ylen float Cell dimensions (Angstroms)
MRC.zlen float Cell dimensions (Angstroms)
MRC.alpha float Cell angles (Degrees)
MRC.beta float Cell angles (Degrees)
MRC.gamma float Cell angles (Degrees)
MRC.mapc int Which axis corresponds to Columns
MRC.mapr int Which axis corresponds to Rows
MRC.maps int Which axis corresponds to Sections
MRC.ispg int Space group number (0 for images)
MRC.nsymbt int Number of chars used for storing symmetry operators
MRC.machinestamp int machine stamp in CCP4 convention: big endian=0x11110000 little endian=0x44440000
MRC.rms float rms deviation of map from mean density
MRC.nlabels int Number of labels being used

Parameters from FEI MRC file (an extended MRC format for tomography)

TagTypeDescription
FEIMRC.a_tilt float Alpha tilt, in degrees
FEIMRC.b_tilt float Beta tilt, in degrees
FEIMRC.x_stage float Stage x position. Normally in SI units (meters), but some older files may be in micrometers. Check by looking at values for x,y,z. If one of these exceeds 1, it will be micrometers.
FEIMRC.y_stage float Stage y position. For testing of units see x_stage.
FEIMRC.z_stage float Stage z position. For testing of units see x_stage.
FEIMRC.x_shift float Image shift x. For testing of units see x_stage.
FEIMRC.y_shift float Image shift y. For testing of units see x_stage.
FEIMRC.defocus float Defocus as read from microscope. For testing of units see x_stage.
FEIMRC.exp_time float Exposure time in seconds.
FEIMRC.mean_int float Mean value of image.
FEIMRC.tilt_axis float The orientation of the tilt axis in the image in degrees. Vertical to the top is 0=B0, the direction of positive rotation is anti-clockwise.
FEIMRC.pixel_axis float The pixel size of the images in SI units (meters).
FEIMRC.magnification float The magnification used for recording the images.
FEIMRC.ht float Value of the high tension in SI units. (volts)
FEIMRC.binning float The binning of the CCD or STEM acquisition.
FEIMRC.appliedDefocus float The intended application defocus in SI units (meters), as defined for example in the tomography parameter view.
FEIMRC.remainder float(x128) Not used.

Parameters from EER file

TagTypeDescription
EER.compression int 65001 for EER compressed data 7-bit, COMPRESSION_NONE (1) for final image data
EER.exposure_time float Exposure time of the acquisition in s
EER.total_dose float Average amount of electrons per pixel in the entire acquisition in e/pixel
EER.mean_dose_rate float Average amount of electrons per pixel per second during the acquisition in e/pixel/s
EER.number_of_frames int Total number of frames in the acquisition
EER.sensor_image_height int Height of the individual images
EER.sensor_image_width int Width of the individual images

Parameters from IMAGIC file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_UCHAR, EM_USHORT, EM_FLOAT, EM_FLOAT_COMPLEX
IMAGIC.imgnum int image number, index from 1 to n
IMAGIC.count int total number of images - 1
IMAGIC.error int Error code for this image
IMAGIC.headrec int number of header records/image (always 1)
IMAGIC.mday int image creation date
IMAGIC.month int image creation month
IMAGIC.year int image creation year
IMAGIC.hour int image creation hour
IMAGIC.minute int image creation minute
IMAGIC.sec int image creation second
IMAGIC.reals int image size in reals
IMAGIC.pixels int image size in pixels
IMAGIC.type char(4) PACK, INTG, REAL, COMP, RECO
IMAGIC.ixold int Top left X-coord. in image before windowing
IMAGIC.iyold int Top left Y-coord. in image before windowing
IMAGIC.oldav float old average density
IMAGIC.label char(80) image id string
ptcl_repr int raw images represented by this image. Note: non-standard use
xform.projection Transform particle orientation, set from the orientation flags(alt, az, phi) in the IMAGIC header
xform.align3d Transform particle orientation for 3D image, set from the orientation flags(alt, az, phi) in the IMAGIC header

Parameters from IMAGIC2 file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_UCHAR, EM_USHORT, EM_FLOAT, EM_FLOAT_COMPLEX
IMAGIC.imgnum int image location number (1,2,3,…)
IMAGIC.count int total # images in file (1st record only), total number of images - 1 (0,1,2,…)
IMAGIC.error int error code for this image during IMAGIC run
IMAGIC.month int creation month
IMAGIC.day int creation day
IMAGIC.year int creation year
IMAGIC.hour int creation hour
IMAGIC.minute int creation minute
IMAGIC.sec int creation second
IMAGIC.rsize int image size in bytes
IMAGIC.izold int top left Z co-ordinate before THREED-CUT
IMAGIC.type char(4) 4 characters determining the image type; only 'REAL', or 'INTG' are implemented for EMAN
IMAGIC.ixold int top left X co-ordinate before CUT-IMAGE (boxing)
IMAGIC.iyold int top left Y co-ordinate before CUT-IMAGE (boxing)
IMAGIC.complex int label indicating that data is always complex
IMAGIC.defocus1 float defocus value 1
IMAGIC.defocus2 float defocus value 2
IMAGIC.defangle float defocus angle
IMAGIC.sinostart float start angle if image is a sinogram
IMAGIC.sinoend float end angle if image is a sinogram
IMAGIC.label char(80) coded NAME/TITLE of the image
IMAGIC.ccc3d float 3D similarity criteria
IMAGIC.ref3d int 3D membership
IMAGIC.mident int micrograph identification number
IMAGIC.ezshift int equivalent shift in Z direction
IMAGIC.ealpha int equivalent Euler angle alpha
IMAGIC.ebeta int equivalent Euler angle beta
IMAGIC.egamma int equivalent Euler angle gamma
IMAGIC.nalisum int number of image summed
IMAGIC.pgroup int point-group symmetry in international notation (622, for example)
IMAGIC.i4lp int number of objects in file
IMAGIC.alpha float Euler angle alpha (3D and Angular Reconst.
IMAGIC.beta float Euler angle beta (3D and Angular Reconst.)
IMAGIC.gamma float Euler angle gamma (3D and Angular Reconst.)
IMAGIC.imavers int IMAGIC version, which created the file (yyyymmdd)
IMAGIC.realtype int floating point type, machine stamp
IMAGIC.angle float last rotation angle
IMAGIC.voltage float acceleration voltage (kv)
IMAGIC.spaberr int sperical aberration (mm)
IMAGIC.pcoher int partial coherence
IMAGIC.ccc float cross correlation peak hight
IMAGIC.errar float error in angular reconstitution, if -1.0: the file is a special file (FABOSA)
IMAGIC.err3d float error in 3D reconstruction
IMAGIC.ref int (multi-) reference number
IMAGIC.classno float class number in MSA classification
IMAGIC.locold float location number before CUT-IMAGE (boxing), or before copy in ANG-RECONST and EX-COPY
IMAGIC.repqual float representation quality, used in MSA-RUN and MSA (eigen) filtering
IMAGIC.zshift float last shift in Z direction
IMAGIC.xshift float last shift in X direction
IMAGIC.yshift float last shift in Y direction
IMAGIC.numcls float number members in the class specified in CLASSNO, if this image represents a class average (class-sum image)
IMAGIC.ovqual float overall quality of the class in CLASSNO
IMAGIC.eangle float equivalent angle
IMAGIC.exshift float equivalent shift in X direction
IMAGIC.eyshift float equivalent shift in Y direction
IMAGIC.cmtotvar float total variance in data matrix relative to center of mass (MSA calculations)
IMAGIC.informat float Gauss norm / real*FT Space information of the data set
IMAGIC.numeigen int number of eigen values in MSA
IMAGIC.niactive int number of active images in MSA calculations
IMAGIC.fabosa1 float Euler angle alpha (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.fabosa2 float Euler angle beta (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.fabosa3 float Euler angle gamma (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.alpha2 float Euler angle alpha (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.beta2 float Euler angle beta (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.gamma2 float Euler angle gamma (from projection matching), Special FABOSA variables if DAT1(105) = -1.0
IMAGIC.nmetric float Metric used in MSA calculations
IMAGIC.actmsa float a flag indicating whether the “image” is active or not. Used during MSA calculations
IMAGIC.coosmsa float(69) co-ordinates of “image” along factorial axis
IMAGIC.history char(228) coded history of image (228 characters)
ptcl_repr int raw images represented by this image. Note: non-standard use
xform.projection Transform particle orientation, set from the orientation flags(alt, az, phi) in the IMAGIC header
xform.align3d Transform particle orientation for 3D image, set from the orientation flags(alt, az, phi) in the IMAGIC header

Parameters from SPIDER file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_FLOAT
SPIDER.nslice int number of slices in volume; 1 for a 2D image
SPIDER.type int file type
SPIDER.irec float total number of records in the file (unused)
SPIDER.angvalid int 1 if tilt angles have been computed
SPIDER.phi float tilt angle phi
SPIDER.theta float tilt angle theta
SPIDER.gamma float tilt angle gamma
SPIDER.headrec int number of records in header
SPIDER.headlen int header length in bytes
SPIDER.reclen int record length in bytes
SPIDER.dx float x translation
SPIDER.dy float y translation
SPIDER.dz float z translation
SPIDER.istack int 0 for simple 2D or 3D (non-stack) files. for stacked image, istack=2 in overall header, istack =-1 in following individual images.
SPIDER.maxim int maxim is only used in the overall header for a stacked image file. It is the number of the highest image currently used in the stack. The number is updated, if necessary, when an image is added or deleted from the stack.
SPIDER.imgnum int imgnum is only used in a stacked image header. It is the number of the current image or zero if the image is unused.
SPIDER.Kangle int flag that additional angles are present in header. 1 = one additional rotation is present, 2 = additional rotation that preceeds the rotation that was stored in words 15..20.
SPIDER.phi1 float
SPIDER.theta1 float
SPIDER.psi1 float
SPIDER.phi2 float
SPIDER.theta2 float
SPIDER.psi2 float
SPIDER.date char(11) creation date
SPIDER.time char(8) creation time
SPIDER.title char(160) title
SPIDER.scale float scale factor
xform.projection Transform particle orientation, set from the orientation flags(phi, theta, psi, tx, ty, tz, scale) in the SPIDER header
xform.align3d Transform particle orientation for 3D image, set from the orientation flags(phi, theta, psi, tx, ty, tz, scale) in the SPIDER header

Parameters from PGM file

TagTypeDescription
PGM.max_gray int maximum value for grey level
PGM.min_gray int minimum value for grey level

Parameters from SAL file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_SHORT
SAL.pixel float pixel size

Parameters from TIFF file

TagTypeDescription
datatype int pixel storage data type in EMAN format: EM_UCHAR, EM_USHORT, EM_FLOAT
TIFF.bitspersample unsigned short bits per pixel sample
TIFF.resolution_x float x dimension resolution
TIFF.resolution_y float y dimension resolution

Parameters from Gatan DM3 files

TagTypeDescription
DM3.acq_date string Acquisition date
DM3.acq_time string Acquisition time
DM3.actual_mag float Calibrated magnification
DM3.antiblooming int
DM3.binning_x int Binning (X)
DM3.binning_y int Binning (Y)
DM3.camera_x int Camera size (X)
DM3.camera_y int Camera size (Y)
DM3.cs float Microscope Cs
DM3.exposure_number int Camera exposure number
DM3.exposure_time float Exposure time
DM3.frame_type string Frame type
DM3.indicated_mag float Indicated magnification
DM3.name string Filename
DM3.pixel_size float Pixel size (microns)
DM3.source string Camera name
DM3.voltage float Microscope voltage
DM3.zoom float

Parameters from XPLOR file

TagTypeDescription
apix_x,y,z float Angstroms per pixel on the x-axis (also _y and _z). If _y or _z are 0 or not present it will be assumed that they are the same as _x. Note that CTF objects have an independent value for A/pix
XPLOR.alpha float alpha angle of the cell
XPLOR.beta float beta angle of the cell
XPLOR.gamma float gamma angle of the cell
eman2/metadata.txt · Last modified: by steveludtke