(a) (b) (c) 
Figure 8. Homomorphicaly Filtered Test Image#l (a) 
Photocopy filter (Det: 20, dark:5) (b) Threshold (Level:165) (c) 
overlay with original image 
6.3 Find Edges — Photocopy — Trace Contour 
Find edges in “Stylize” section of filters in Photoshop menu 
highlights the areas with dramatic transitions and extracts the 
edges. It can be used for creating borders around an image area 
or around a specific pattern in an image. 
  
   
  
  
  
  
  
  
  
(a) (b) (c) 
Figure 9. Homomorphicaly Filtered Test Image#1 (a) Find 
Edges (b) Photocopy filter (Det: 5, dark:5) (c) overlay with 
original image 
7. QUANTITATIVE ANALYSIS WITH PHOTOSHOP 
Quantitative analysis on skin disorders is very important in 
order to see the evaluation of a disease. Analysis done by only 
visual observation by doctors is observer-dependent (Ramazani 
et al.) and moreover small changes might not be recognizable 
by human vision. Photoshop provides a user-friendly and 
amount effective tool to answer this purpose. 
In this part of the study (as well as in the filter testing phase), 
Photoshop 7.0 was used to make quantitative analysis. Two 
images with different dimensions of the same scar on skin were 
analysed. Because of the inability to access real patients, the 
tests were applied on printed images downloaded from the 
internet. It should be noted that, to make a final judgment about 
the validity of all Photoshop tools, more examinations must be 
done with the contribution of medical specialists and on real 
patient's skin diseases. Quantitative analysis was performed 
using two different tools of Photoshop: *Magic Wand" and 
"Magnetic Lasso". These tools determine the size of the scar in 
pixel dimensions that can be used for a reliable metric 
evaluation comparison. The mentioned methods were applied 
on the same scar images but with different characteristics (size). 
All image pairs were registered on each other and were 
converted to the same ground space in order to make the 
comparison feasible. This way it was possible to define some 
standards for this kind of temporal images’ comparison and 
to reveal the usefulness of the applied filters. 
7.1 Magic Wand Tool 
The Magic Wand tool specifies the adjacent area around a pixel 
which is selected by the operator. Two criteria, tolerance value 
and contiguous option, must also be determined. Tolerance 
value in pixels ranges between 0 and 255. This value must be 
selected low if it is preferable to select very similar pixels to the 
operator's choice. Higher values widen the range of pixel 
  
     
  
   
   
      
      
      
       
          
   
  
    
    
    
    
    
   
   
   
  
  
    
    
     
     
    
    
   
differences between each other (Adobe Photoshop Help 
Center). 
Contiguous selection allows neighbouring pixels to the 
operator's selection to be taken into consideration for the final 
selection of the area. Otherwise, only the similar pixels (within 
the given tolerance) will be taken into consideration 
Tolerance was chosen as 30 and contiguous option was used 
during the application. The histogram under the image menu 
shows mean, median, standard deviation and pixel amount 
within the selection. 
Results after ten trials on both homomorphicaly filtered Tes; 
Image#l and Test Image#2 are displayed below in Table.! and 
Table.2 
Tablel. Magic Wand process on 
Homomorphicaly Filtered Test Image#1 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
5 Std. Tot. 
No. Mean | Median Dev. Pixels 
1 116.43 114 9.37 3374 
2 115.17 114 7.41 3226 
3 114.84 114 6.93 3181 
4 114.75 114 8.82 3167 
5 114.86 114 6.94 3183 
6 115.10 114 7.34 3213 
7 114.75 114 6.82 3163 
8 115.27 114 7.33 3238 
9 114.46 114 7.41 3226 
10 115.17 114 7.41 3226 
  
Table2. Magic Wand process on 
Homomorphicaly Filtered Test Image#2 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
: Std. Tot. 
No. Mean | Median Des. Pixels 
1 128.32 127 7.19 2401 
2 128.64 127 7.67 2434 
3 128.19 127 7.04 2385 
4 128.32 127 7.19 2401 
5 128.17 127 7.01 2383 
6 129.01 127 8.22 2469 
7 129.05 127 8.25 2473 
8 128.83 127 7.94 2452 
9 128.39 127 7.33 2407 
10 128.15 127 7.34 2350 
  
7.2 Magnetic Lasso Tool 
The Lasso tool lets the operator to draw borders freely while the 
magnetic lasso tool snaps the border to the edges of the defined 
areas in the image. Anti-aliasing smoothes the edges and the 
feathering feature blurs the edges between the selection and its 
surrounding pixels. There are some extra options to determine 
the use of the magnetic lasso tool. Width value in pixels 
indicates the amount of the neighbor pixels which will be 
included into border. Edge Contrast is the sensitivity to edges 
in image. Higher values detect only edges that differs highly 
contrast with its surroundings and lower value allows lower 
contrast selection. Frequency specifies the rate between 
fastening points of lasso tool. Higher frequency means close- 
timbered selection will be done by software (Adobe Photoshop 
Help Center). 
While using Magnetic Lasso tool, anti-aliasing and feather 
choices were left to 0 because smoothness and blurriness is 
considered to cause loss of information and make the selection 
of edges harder. The selection width of 24 pixels (in diameter) 
was left unchanged as it was originally selected by the software; 
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Wand tool