![](bg5.png)
4.5 times higher at the maximum digital zoom-in
(587/130= 4.5).
The onScreen RGB images built with half
sampling density then required improved by 4.5
times the UM to enter in the so called empty
magnification.
In Figure 2 & 3 A-B we can analyze several
zoom-in and zoom-out SM.
4 DISCUSSION
The present paper demonstrates how digital
pathology behave as a computer assisted
microscopy, because helps to detect details that
escape to human eye in the so-called type I low
aperture (NA<0.5) widefield incoherent light
systems. In other words hybrid systems (in which
optical and digital modules are part of the same
system) could improve resolution and specifically
the CCD systems improve system resolution by 2
(Torok, 2007).
In the presented system, all improvements were
low cost computation algorithms: (1) noise reduction
increasing depth of field by 16 image averaging, (2)
attenuated frequencies were amplified with LRGB
images that correct the limited light gathering
(proportional to NA
2
) of low-NA lenses, and (3)
phase recovery improving modulated transfer
function with an adaptive contrast enhancement.
The displayed RAW-color demosaicing images
reached the superresolution level (Nugent, 2003)
(Lipson, 2003) even without an optimal digital
resolution.
Projection magnification onChip (PMoC) is
essential to evaluate the system sampling
capabilities and Digital Resolution-DR influence
visibility and digital image quality with or without
computer assisted techniques.
OnScreen differences for RAW and RGB images
were due to higher DR and contrast enhancement
with light gathering provided by superresolution
algorithms on the RAW images.
Capture is furthermore influenced by Chip
quality. Most photographic cameras have 5-9 μm
pixel size and big size chips. Microscopy requires
smaller chips to avoid aliasing (Koren, 2000-2009)
and therefore smaller pixel size; this provides more
noise and less sensitivity increasing the cost. This is
the reason why high resolution cameras with high
SNR are require in microscopic imaging.
Nowadays the public consume CCDs and CMOS
chips for imaging are improving. Being the CMOS
more noisy but cheaper solutions. There are ultimate
regeneration of mobile phones that contain a 12
Megapixel cameras and therefore provide high
digital resolution due to the high sampling. Those
hand-held solutions including the 4M microscopes
only require to be considered in pathology
appropriate objective lenses and illumination system
preferable base on leads (Ferrer-Roca, 2005).
One of the main drawbacks for distant diagnosis
in pathology (telepathology) is sampling error
because the essential part of the specimen is not seen
because it was not completely digitized. The
solution to this is to digitized the whole specimen
building a Virtual Slide. The usual VS technique
captures images using 40x objectives because
optical resolution is adequate (0.29 μm); the result is
a huge image (around 10 GB) difficult to handle,
that require time consuming compression techniques
on which we cannot control lost information and that
is difficult to store in the hospital information
systems based on DICOM, because the limit image
size is 2 GB (Dicom, 2007).
The technique presented here not only provide
small images but zoom-in and zoom-out capabilities
never explore by pathologist (Ferrer-Roca,
2005)(Marcano, 2007; 2006). As shown in the paper
the image showed a super-resolution level to which
the oversampling and the super-resolution algorithm
applied played a role.
The paper demonstrated the methods to evaluate
image quality on computer assisted microscopes
displaying digital images. The analysis was focused
on resolution and visual magnification in order to be
able to apply it to various capture systems for distant
diagnosis ( 4M, mobile phones…).
In summary: The SSVS technique implemented
in the TEXCAN-II™ demonstrated that image
diagnostic capabilities are higher than analogical
image seen in the microscope because they are
capable to produce intermediate and high power
microscopic magnification entering in the empty
magnification showing super-resolution details. The
technique of specimen navigation and ROI detection
simplify and facilitate diagnosis at distance and
prepare the era of the hand-held microscopes based
on 4M or integrated into the mobile phones.
REFERENCES
DICOM strategic document (2007); [cited 2007 Dic 31st].:
http://medical.nema.org/dicom/geninfo/Strategy.pdf
Ferrer-Roca O. (1998) Telepathology. In Ferrer-Roca O,
Sosa-Iudicissa M. in Handbook of Telemedicine.
Amsterdam: IOS-Press, 1998; pp. 70-5
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