The document discusses developing an open source print quality assessment program using the Fiji/ImageJ environment. It outlines that Fiji/ImageJ allows for free and flexible development of such a program using Java. It then provides examples of specific print quality features that could be extracted and analyzed such as line width, dots, color variations, and placement accuracy. The goal would be to increase productivity and automation for print quality evaluation.

2.  Commercial systems dedicated to assess print quality already
exist. They usually implement the ISO 13660 standard with a
focus on character and line attributes (raggedness, line
width, darkness, character, contrast, fill, extraneous marks,
character field, background haze, character field)
 However, they are expensive, lack of flexibility and the access
to their algorithms is not possible.
 Fiji/ImageJ and its environment enables to develop an open
source program dedicated to print quality assessment
› free license
› Interface based
› Development using Java language and pre-coded functions
› Enhance collaboration

3. Print target
design
Choice of Printing System model
relevant features
Image
Printing sequences Printing parameters
(drop speed,…) acquisition
Features
Substrate High resolution &
low field of view extraction
Ink vs low resolution
Lines Statistical
& high field of
Printing
view analysis
configuration Dot
Lighting Text Intra-samples
Dithering conditions
techniques Registration mark Inter-
samples
Fiji

4.  Fiji is an image processing package. It can be
described as a distribution of ImageJ together
with Java, Java 3D and a lot of plugins.
 User interface
 Macro/plugings editor

5. Individual ‘bricks’
-Color conversion Software development
-Binary analysis Macro
-Illumination correction Java based program
-…
Increase productivity
Automation
Shorter development time
Proprietary routines and
development of standard

6.  Image creation to design test charts
 Dithering techniques
 Dots and satellites
 Line width/raggedness
 Series of parallel lines

7.  By example, test of optical density regularity
along the swathe
› Periodic pattern
› Random pattern

8.  Comparison and impact of different
dithering techniques
 Implementation of algorithms specific to
greyscale printhead

9. Particles extraction
Particles counting
Background subtraction
RGB – one layer
Binarization

10. Individual object’s properties
Histogram for a given
parameter

11. › Edges extraction + angular correction +
average and standard deviation on both
sides of the line

12.  Idea The centre of each line is
computed to obtain the The histogram is then
Original image distance between two plotted
successive lines
Histogram
%
di
di
REFERENCE

13.  implementation
The red circles represent
the middle of the line
Average and standard
deviation are then calculated

14.  Colour deconvolution
 Results tolerance
 Text recognition and limit of
“readability”

15.  Objective: to quantify colour variations caused by
due to undesirable drops overlap,...
Placement
accuracy
% of
coverage
Printing
Colour Colour
direction
clustering split
in RGB Dithering
space techniques

16.  Objective: to evaluate the interval of confidence for
results like dot diameter, (x,y) positioning, roundness,…
Pixel size: 2 µm Distribution of error centred of the
Dot diameter: 60 µm theoretical dot area
Algorithm based
on dot permutation

17.  Image analysis is an approach, but not
the end of the story
 PQ can be described along several others
physical dimensions (Optical density,
colour gamut, full tone uniformity…)
 Some levels of overlapping exist between
them

18.  If you:
› want to know more about ImageJ / Fiji
› are interested in developing an ISO13660
open source software
› have a specific need regarding print quality
assessment, beyond image analysis
 I would be please to heard from you.