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Methodology: Creating Templates.
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To create the image template, the individual skeletal elements were photographed
from each of the directional views (i.e. anterior, posterior, lateral and
medial together with proximal and distal views if applicable). A digital
camera was used for the purpose (Fuji Finepix S602 Zoom digital camera without
any modifications or special attachments) creating a standard JPEG format
image, 2832 x 2128 pixels in size with 72 pixels per inch resolution; these
images were then downloaded into a personal computer. All manipulation and
template creation was carried out using Paint Shop Pro 5
(Jasc Software 1998), firstly using the
software's suite of selection tools to select and "lift" the bone out of
the digital photograph. After checking and neatening the individual images,
their size was standardised and then they were incorporated into the single
composite template. Finally the necessary labels were added to the template.
All file formats used were Paint Shop Pro's own format with a "psp" extension
which makes these particular files usable only in the Paint Shop Pro programs.
However as stated earlier the files can be converted to other graphic program
formats.
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The use of a computer has particular advantages when creating digital image
templates; for example, for the sided skeletal elements only one side was
photographed and incorporated into a template. To create the template for
the opposite side the software's "mirror" function was used to create an
exact copy for the opposite side (figs 2(a) & 2(b).). Another example
is the combining of parts of images to digitally "repair" the image of a
bone. This was specifically used for the tibia image; both bones had some
erosion of their proximal epiphyses (fig. 3(a).), by copying the patella
area from one image to the other a complete bone image could be created for
use as a template (fig. 3(b).).
Fig. 2(a). Both tibias had errosion present.
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Fig. 2(a).
The original image of the left femur (anterior view).
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Fig. 2(b).
The right femur image created using the software's mirror function.
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Fig. 2(b).
By transposing the patella area from one bone to the other a complete template
image is created.
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Once the image template had been created, the graphic program's selection
tools together with its features for edge definition, selection tolerances
and merging were used to define an edge to each bone image in the template.
By creating a line from this edge and blanking out the image, a perfectly
aligned line template for the bone was created. This was incorporated into
the basic template so that it could be used interchangeably with the image.
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