imodchopconts(1) General Commands Manual imodchopconts(1) NAME imodchopconts - Chop up contours in IMOD model based on length or color SYNOPSIS imodchopconts [options] input_model output_model DESCRIPTION This program will chop contours into pieces in two different ways. In one mode, it will produce contours with equal numbers of points, and with a specified amount of overlap between the pieces. This mode of operation has two main uses: 1) Breaking up the contours produced by patch tracking with Tiltxcorr into overlapping pieces, which can give a better fit in Tiltalign. 2) Splitting up scattered point contours so that there is one point per contour. However, it could also be used to split up contours into other lengths, with or without overlap. In its other mode of operation, the program will break con- tours apart at fine-grained color changes between points, and put the new contours into separate surfaces or separate objects. Whole con- tours that are a different color because of a fine-grained contour color property will also be sorted into different surfaces or objects. The color can thus be changed at the surface or object level for all contour segments of the same color, which is otherwise difficult. Breaking contours apart in this way also allows quantitative analysis to be done on separately colored segments by programs that do not take account of fine-grained color changes. Specifying positive numbers for the -length and -overlap options here has exactly the same effect as providing those two numbers to the -length option of Tiltxcorr. When doing length-base chopping, fine grained information at the point level will be preserved in the newly created contours. Fine-grained information for an individual contour will be transferred to each of the new contours derived from it. Surface-level fine-grained informa- tion will also be preserved unless the -surfaces option is given. When doing color-based chopping, all line segments will be appear with their original colors for open or closed contour objects. This requires a duplication of points at the contour endpoints. However, there is no such duplication of points for scattered point objects. Fine grained information will be preserved during color-based chopping to the extent that it makes sense. Specifically, fine-grained proper- ties at all three levels (point, contour, or surface) will be preserved in the new contours, except for color. The color is not lost, but is incorporated into the surface or object to which the derived contours are assigned and is thus removed as a fine-grained property. Contour level fine-grained properties are transferred from the original contour to each contour derived from it. Surface level information is trans- ferred differently depending on whether contours are assigned to sur- faces or objects. In the latter case, the derived contours have the same surface number as the original one, and all non-color surface information is copied to each new object. When derived contours are assigned to new surfaces, surface information that applies to the orig- inal contour is duplicated for the new surfaces. If for some reason your model has surface-level fine-grained data, it will probably be preferable to split contours into new objects, to avoid a proliferation of surfaces. OPTIONS Imodchopconts uses the PIP package for input (see the manual page for pip). Options can be specified either as command line arguments (with the -) or one per line in a command file (without the -). Options can be abbreviated to unique letters; the currently valid abbreviations for short names are shown in parentheses. -input (-i) OR -InputModel File name Name of input model file. If this option is not entered, the first non-option argument will be taken as the input file. -output (-ou) OR -OutputModel File name Name of output model file. If this option is not entered, the second non-option argument will be taken as the output file. -length (-l) OR -LengthOfPieces Integer The length of the new contours, i.e., the number of points to put in each. The actual length can be affected by the entry for -overlap. If -1 is entered and the -number option is not, the length will be the default for breaking up contours from patch tracking in Etomo, which is the Z size in the model divided by 5, but no less than 16. The default if neither this option nor -number is entered is to leave contours as they are. Unless this option is entered with a -1, it cannot be entered with -number. -overlap (-ov) OR -MinimumOverlap Integer The minimum number of points overlapping between pieces. If the minimum overlap is 0 or positive, then all new contours will be given the same number of points, but both the overlap and the number of contours will vary depending on the length of the original contour. Enter -1 to enforce zero overlap between con- tours and have the contours broken into variable lengths, typi- cally less than the specified length. The default is 4, unless 1 is entered for -length, in which case the default is 0. -number (-n) OR -NumberOfPieces Integer This option provides an alternative way to specify how to chop up contours. The maximum number of points in any contour to be processed will be divided by the given number to determine the number of points to require in each new contour. This option cannot be entered if -length is entered with a value greater than 0. -surfaces (-s) OR -AssignSurfaces Give each new contour a surface number equal to the number of the contour from which it came. This will replace any existing surface numbers and invalidate any fine-grained information that applies to surfaces. -colors (-c) OR -BreakAtColors Integer Break contours at fine-grained color changes, assigning them to new surfaces or new objects with the appropriate color if 1 or 2 is entered, respectively. None of the options related to length-based chopping (-length, -overlap, -number, or -surfaces) may be entered with this option. See above for details. -objects (-ob) OR -ObjectsToDo List of integer ranges List of objects to chop up, a comma-separate list of ranges. The default is to chop up all objects. -help (-h) OR -usage Print help output -StandardInput Read parameter entries from standard input AUTHOR David Mastronarde SEE ALSO tiltxcorr BUGS Email bug reports to mast at colorado dot edu. IMOD 4.11.0 imodchopconts(1)