MIPPS

Features

MIPPS supports the following features through filters.

Radiometric correction

PRNU/DSNU
Parametric devignetting

Geometric correction with the following mathematical models

DOE undistort
Pictran undistort
Luhmann

Tone mapping

Linear stretch
Automatic stretch through histogram analysis
Gamma correction
Color tables

Export to the following formats (among others)

JPEG
8 or 16 bit TIFF
DNG

Usage

MIPPS converts (develops) images through a so called MIPPS script.

The application is both an editor of MIPPS scripts and a tool to apply a script to a directory of MACS image files.

Once you have a MIPPS script (see below for how to create one) you can apply it to your images through one of two modes.

Exporting through the graphical interface

In order to try out the script you are editing, you can select one or several images in the file browser, right click and pick "Export selected files" and select an output directory in the configuration dialog.

Command line processing

You can access the documentation of MIPPS command line flags by opening a console and typing `mipps -h`. You should see the following output:

MIPPS -h output

This is MIPPS - Matrix camera Image PreProcessing Suite (0.8.6365ed1a build: Wed 21/17/03)
(C) 2012-2021 by DLR / OS-ASK

Usage: mipps.exe [OPTIONS] image files or directory
 OPTIONS:
 -help, -h            show this help text
 -version             show version information
 -verbose, -v         show additional information during processing
 -config=x, -c=x      specify a MIPPS config file describing the filters to be
                      applied
 -output-dir=x, -o=x  choose target directory for the processed files (by
                      default output is written to the current directory.)
 -logfile=x, -l=x     Redirect all log messages to this file.
 -terminal, -t        Force log output to the terminal (even if file logging is
                      enabled).
 -jobs=x, -j=x        Number of jobs to run in parallel.

In the simplest case you can batch convert a directory by calling

>mipps -c=<mipps-script> -o=<out_dir> <macs_img_dir>

Editing a MIPPS script

A MIPPS script is edited by adding and modifying filters in the filter list window. Filters are added and removed with the +/- buttons and can be rearranged with the ↑/↓ buttons.

Selecting a filter (clicking on it in the list) makes the filter properties available for editing in the window below.

❗Don't forget to add a Write filter at the end or your script will only have effect in preview mode.

Previewing changes

Filter modifications made in the properties window will immediately take effect in the image preview window. Only filters up to and including the on you have selected will be applied in the preview.

You select the image to preview through "File" → "Open Image", or select one in the "File browser" window

Filter parameters

These are the parameters for the most common filters.

DSNU

The DSNU filter corrects each pixel with the following formula.

$\begin{array}{l}\displaystyle pix_{corrected}(i,j) = (pix(i,j)-offset(i,j)) * factor(i,j)\end{array}$

Typically, The DSNU filter will be generated by Image Calibrator as a step of the Camera calibration and won't be edited by the user.

Parameter name	Meaning	Default
offset	This value will be subtracted from every pixel in the image.	0
factor	Every pixel in the image will be multiplied with this value.	1
OffsetImage	If provided, the values in the linked file will be used as offsets on a per pixel basis.	<none>
FactorImage	If provided, the values in the linked file will be used as factors on a per pixel basis.	<none>

Debayer

The debayer filter reconstructs a full RGB image from a single channel raw image.

Parameter name	Meaning	Default
mode	Selects which debayering method to be used	DebayerBilinear

The most common modes are bilinear, which is the simplest and fastest but suffers from color fringing around edges, and DCB, which is more processor intensive, but tries to keep edges intact.

None	Mosaic	Bilinear	DCB

A demonstration of different Debayering methods.

Devignetting

The vignetting factor df is modeled as $\begin{array}{l}df = (1.0 + a*r^2 + b*r^4 + c*r^6)\end{array}$ , where $\begin{array}{l}r\end{array}$ is the normalized distance from the image center ( $\begin{array}{l}-1 \le r \le1\end{array}$ ).

Typically, The DSNU filter will be generated by Image Calibrator as a step of the Camera calibration and won't be edited by the user.

a

Parameter name	Meaning	Default
a,b,c	Devignetting coefficients	0
cx, cy	The radiometric center (normalized; (0;0) is image center, (1;1) is bottom right)	0

Write filter

A MIPPS-script will almost always end with a Write filter.

The output filename will be <prefix><basename><suffix>.<ext>.

It is possible to have several Write filters in one script. A common use for this would be to export one directory of 8-bit and one of 16-bit images.

Use a Linear-Stretch and Gamma filter before writing a 16 bit image to a 8-bit image format to define the tonemapping (brightness of the written image).

Parameter name	Meaning	Default
format	The image output format. The most common are tiff, tiff16, jpg, dng.	tiff16
prefix	A typical prefix will be "images/" or "thumbnails/"	""
suffix	A typical suffix would be "_large" or "_raw".	""
quality	Parameter passed to the jpg encoder. Affects the quality/file size trade off.	100
compression	This flag will activate lossless LZW compression for tiff16 images. YMMV	false

Linear-Stretch

Applies a linear tone mapping to the image. See this video for a sense of what min max and gamma means.

Parameter name	Meaning	Default
min	The 'black level'	0 %
max	The 'white level'	100 %

Gamma

Applies a gamma correction to the image.

Parameter name	Meaning	Default
gamma	Gamma factor applied to the image.	1
mode	If PerChannel is selected, a different gamma factor will be applied to each channel	Global
gamma red\|green\|blue	Per channel gamma factor. Ignored if mode=Global.

Auto-stretch

The auto-stretch filter will apply a linear stretch of the image based on a histogram analysis of the image content.

It is useful to produce 8-bit thumbnails that are never over- or underexposed.

Parameter name	Meaning	Default
min	After stretching min % of the image will be black.	1%
max	After stretching max % of the image will be white.	1%

Color map

Creates a "false color" image from a single channel image based on a preselection of color maps.


A selection of color maps.	The color map Jet applied to a thermal image

Parameter name	Meaning	Default
Color map	Which color map should be applied	"Jet"