RAYGRAFProject financed by

the Ministry of Science and Higher Education in Polandfrom funds on science in years 2009 – 2011 as development project

Software producer and distributor:

Research and Training Centreof Polish Forensic Association

www.kryminalistyka.pl

Programme Guide

The PolishForensicAssociation

Universityof Warsaw

Authors of software:Andrzej Łuszczuk M.Sc.

Krystyn Łuszczuk M.Sc. Eng.

Scientific consultation:Prof. Tadeusz Tomaszewski

Dr Mieczysław Goc

English version:Agnieszka Łukomska (M.A.)

System and equipment requirements:

TO ENSURE PROPER RUNNING OF PROGRAMMETHE FOLLOWING REQUIREMENTS SHOULD BE MET:

2. IMPORTANT: required monitor (display) resolution 1024 × 600 or higher. In lower resolution, the programme cannot be started.

3. Recommended default font size "9" at 96 dpi (not more than 120 dpi).

4. In Windows „.NET Framework" platform in v.2.0.50727 or more recent version should be installed. It is necessary for proper running of the programe.

1. Operating system: Windows XP, Windows Vista, Windows 7 or Windows 8.

Applied graphometrical examination methods and

definitions have been elaborated by authors of programme

Definitions

Total width of specimen - distance between extreme points of first and last graphical elementof examined specimen.

Graphical element of specimen - fragment of specimen, which has been drawn with one impulse, having its beginning and end; can be separated from but also constitutes the specimen:letter, morpheme, syllable, digraph, word.

Width of graphical element - distance between extreme points of graphical which constitutesa graphical element.

Spacing between graphical elements of specimen - distance between graphical sets of specimen, resulting from motoric habit of writer.

Width of spacing between graphical elements of specimen - distance between extreme points of consecutive elements, i.e. between ending point of preceding element and starting pointof the following element.

Base segment - line which links the points of the same location in both specimens, and constituting the base for matching of those points (horizontally and in relation to size).

Length (height) of graphical element - segment which links the highest and lowest points of graphical element, designated by parallel lines framing a given graphical element.

Slope of graphical element - angle between the core of axis of symmetry of graphical element and base segment, after it has been leveled.

RAYGRAF programme enables the verification of text similarity with application of the following

methods:

Analysis of lengths and slope angles

Handwriting density analysis

Impulse density analysis

Base segment. The length of this segment in both specimens serves to carry out their

horizontal and size-related „match”

L1

L2

L3

L4L5

L6

α2α6

OPTION I - Analysis of lenghts and slope angles

Angles have been marked for demonstration purposes (for better legibility)only for two elements, i.e. L2 and L6.

The programme calculates them for all designated elements.

y

x

P2 Ending point

α

L

Axis Y

Axis X

Angles are always measured in radians "to the left" from X axis (counterclockwise).

P1(x,y)Ending point

αL

To remind: 360 ⁰ = 2 * π rad = 2 * 3,14 = 6,28 rad1 rad ≈ 57,325⁰ 1⁰ ≈ 0,017 rad

OPTION I

Starting point

Beginning of coordinate system is always in starting point of graphical element.

Lenght of graphic element 22 yxL )(x

yarctgSlope of graphic element

Calculation the lenghts and slope angles

Examined graphic element

Specimen BSpecimen A

OPTION I - Analysis of lengths and slope angles – VERY IMPORTANT

α

β

1. THE SAME NUMBER OF GRAPHICAL ELEMENTS MUST BE DESIGNTED IN BOTH SPECIMEN.2. STARTING AND ENDING POINTS OF ANALOGICAL GRAPHICAL ELEMENTS IN EXAMINED SPECIMENS MUST HAVE IDENTICAL POSITION. Below you find the example of failure to observe this rule.

Change of point sequence is FORBIDDEN. It will cause discrepancy in angles value of nearlyπ radians (180 ⁰) and can entail a significant error in specimen analysis.

Starting point

Ending point

Starting point

Ending point

The lengths of sections (red marked) are identical but their slope angles differ dramatically.

OPTION I - Analysis of lengths and slope angles (cont.).Results of measurements

As results, sequences of measurements of lengths of graphical elements and slope angles are obtained for both specimens:

Sequence of lengths of elements in specimen „A” : La1, La2, La3 ………. Lan

Sequence of slope angles in specimen „A”: α1, α2, α3 ……… αn

Sequence of lengths of elements in specimen „B” : Lb1, Lb2, Lb3 ………. Lbn

Sequence of slope angles in specimen „B”: β1, β2, β3 ……… βn

Then, the differences in lengths and angles of corresponding elements of specimens are determined:

Differences in lengths: ΔL1=|La1- Lb1| ΔL2=|La2- Lb2| ΔL3=|La3- Lb3| …...………….. ΔLn=|Lan- Lbn|

Differences in angles: ΔK1=| α1 – β1 | ΔK2=| α2 – β2 | ΔK3=| α3 – β3 | …...………….. ΔKn=| α3 – β3 |

Red colour indicates differences between elements of specimens A and B < 10%. These

elements were considered as matching.

Green colour indicates differences between elements of specimens A and B (tu odpowiedni znak) 10%. These elements were considered as

non matching.

Total number of examined graphical elements Nog = 6

Number of matching lengths Lzg = 3

Linear coefficientWpl = 100* Lzg/Nog [%]

Wpl = 100*3/6 = 50%

Number of matching angles Kzg = 4

Angular coefficient Wpk = 100*Kzg/Nog [%]Wpk = 100*4/6 = 66,7%

Differences in lenghts[%]

ΔL1 ΔL2 ΔL3 ΔL4 ΔL5 ΔL6

Differences in angles [%]

ΔK1 ΔK2 ΔK3 ΔK4 ΔK5 ΔK6

OPTION I - Analysis lenghts and slope angles (cont.). Graphic show of results (example).

S2S1 S3 S4 S5 S6 S7

Number of graphical elements Nmorf =7 Number of letters in specimen Nliter =9

Scp - Total width of specimen

OPTION II – Handwriting density analysis

OPTION II - Handwriting density analysis (cont.)

After designating of beginnings and ends of graphical elements,

we calculate the following:

Sum of widths of graphical elements Sm = ΣS

Morpheme density coefficient Wgm = Scp/(Sm*Nmorf)

After calculations for both specimens, we determine the following:

Similarity of morpheme density coefficients:100% * Wgm(lower) / Wgm(higher)

Similarity of letter density coefficients:100% * Wgl(lower) / Wgl(higher)

Basing on found similarities of density coefficients, similarity between specimens is verified

Letter density coefficient Wgl = Wgm/Nliter

O1 O2 O3 O4 O5 O6

Number of spaces between graphical elements Nodst = 6

Scp - Total width of specimen

OPTION III – Impulse density analysis

OPTION III – Impulse density analysis (cont.)

After designating of beginnings and ends of spaces between graphical

elements, we calculate the following :

Sum of width of spacing So = ΣO

Impulse density coefficient Wimp = Scp/(So*Nodst)

After calculations for both specimens, we determine the following:

Similarity of impulse density coefficients :100% * Wimp(lower) / Wimp(higher)

Basing on determined similarities of impulse coefficients, similarity between specimens is verified

RAYGRAF

RAYGRAF enables the evaluation of similarity of handwriting specimens basing on 5 parameters:1. Similarity of linear coefficients Wpl2. Similarity of angular coefficients Wpk3. Similarity of morpheme density coefficients Wgm4. Similarity of letter density coefficients Wgl5. Similarity of impulse density coefficients Wimp

The level of measuring accuracy is determined by expert within an acceptable percentage rangeto account for the differences between specimens being compared (5%; 10%;15% i 20%).

Lengths of graphical elements marked by expert

Slope angles of graphical elements marked by expert.

OPTION I – Analysis of lengths and slope angles (example)

Results of linear and angular similarity

OPTION II – Handwriting density analysis (example)

Similarity coefficients Wgm i Wgl

OPTION III – Impulse density analysis (example)

Similarity coefficients Wimp

Basic principles of verification of handwriting

specimens in RAYGRAF

RAYGRAF is a measuring tool, which examines geometrical shape of specimens. It does not account for other features

(such as tremor, points of stoppage, shading distribution) which may appear in examined specimens and be in conflict with high

geometrical similarity.

PROGRAMME IS A MEASURING TOOL AND DOES NOT INTEND TO SUBSTITUTE THE EXPERT

A final decision on match of examined entries belongs to the user !!!

You are welcome to use our programme