micmac processing files
There are a number of files that you will need to process your images using MicMac, which are detailed below. If you
are working with KH-9 images, generate_micmac_measures will automatically create the
necessary files - you only need to move MeasuresCamera.xml
into the Ori-InterneScan
directory.
You can use the provided MicMac example files as a starting point, though note that you will probably need to make some modifications as detailed below.
MicMac-LocalChantierDescripteur.xml
Note
For KH-9 Hexagon Mapping Camera images, you can use spymicmac.micmac.create_localchantier_xml()
or
create_localchantier_xml to generate this file.
Alternatively, you can
download
and edit the example provided.
You will need to set the image size (in mm) by changing the values in SzCaptMm
under CameraEntry
(line 8 of the
example). You will also need to set the image matching pattern (PatternTransform
, line 29 of the example) and focal
length in mm (CalcName
, line 30) for each set of images - if, for example, different focal lengths were used.
To improve tie point density and matching, especially in low-contrast images, you can try copying the block below
into your MicMac-LocalChantierDescripteur.xml
file:
<KeyedNamesAssociations>
<Calcs>
<Arrite> 1 1 </Arrite>
<Direct>
<PatternTransform> .* </PatternTransform> <!-- Regular expressions of the group of images with the following camera model -->
<CalcName> SFS </CalcName> <!-- Name of the camera for these images -->
</Direct>
</Calcs>
<Key> NKS-Assoc-SFS </Key>
</KeyedNamesAssociations>
Note
Be sure that when you paste the block, you paste it so that it is in between the ChantierDescripteur
tags
(lines 2, 36 in the provided example file), and also not within one of the existing KeyedNamesAssociations
blocks. (i.e., paste it at line 23 of the provided example file).
MeasuresCamera.xml
Warning
This file must be placed in a directory called Ori-InterneScan
Ideally, you will have a camera calibration report, that will tell you the location
of the different fiducial markers in the image geometry. Note that using ReSampFid
requires a file,
Ori-InterneScan/MeasuresCamera.xml
, that tells MicMac what the location of each fiducial mark is.
Note
The image coordinates are defined with the origin in the upper left corner, rather than the center of the image used by most calibration files. You can translate from one system to the other with the following:
xp = x - min(x)
yp = (-y) - min(-y)
If you do not have a calibration report for your particular camera, you can have a look at some example camera models for approximate locations of fiducial markers.
Rather than editing the MeasuresCamera.xml
file with the fiducial marker locations, you can also put the fiducial
marker locations into a CSV file, then use spymicmac.micmac.create_measurescamera_xml()
to convert
this create Ori-InterneScan/MeasuresCamera.xml
.
id_fiducial.txt
This is just a plain text file, with the “names” of the different fiducial marks:
P1
P2
P3
… and so on.
Note
The names in the file should match the names written in MeasuresCamera.xml
.
file structure
Before starting, your file structure should look something like this:
project
├── id_fiducial.txt
├── Img1.tif
├── Img2.tif
...
├── MicMac-LocalChantierDescripteur.xml
├── Ori-InterneScan
│ └── MeasuresCamera.xml
Once you have this set up, you can work on the preprocessing steps.