Good morning and welcome! My talk on Image Quality Good morning and welcome!

75 Pages·2012·5.78 MB·English

GGoooodd mmoorrnniinngg aanndd wweellccoommee!! MMyy ttaallkk oonn IImmaaggee QQuuaalliittyy
will be pretty basic. Please forgive some repetition for
those of you here last year. (hand out questionnaires).
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WWee’llll ddiissccuussss aa ffeeww ssttaattiicc,, ddyynnaammiicc aanndd sstteerreeoo ffaaccttoorrss,,
with one stretch midway through. I am no simulator
expert. I have never been to an IMAGE conference or
Simulation school.
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MMyy pphhiilloossoopphhyy iiss ddeeaadd ssiimmppllee – tthhee cclloosseerr oouurr iimmaaggeess
approach our perception in the real world, the better the
image quality. But don’t take my word for it – test it
yourself in your work. So let’s do a little 5 min puzzle
experiment to get you warmed up. (Cone experiment –
wwhhiittee bbooaarrdd – wwiitthh vvootteess))
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OOnnee iiddeeaa II hhooppee yyoouu rreemmeemmbbeerr iiss tthhaatt MMTTFF iiss mmoorree
important than Brightness. MTF stands for Modulation
Transfer Function, but basically you can think of it simply
as resolution to start. What other static metrics are
important for Image Quality?
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HHeerree aarree aa ffeeww.. IIff wwee llooookk aatt aa GGrraayy ssccaallee wwee ccaann rreeaadd
the differing brightness of each step from a screen and of
course we do care about that luminance. Obviously
higher MTF allows us to see finer detail just as higher bit
depths and adequate gamma gives us finer colour
rreessoolluuttiioonn. WWee nneeeedd eennoouugghh ccoonnttrraasstt ttoo sseeee oobbjjeeccttss ooff
interest clearly. We need a wide enough colour gamut to
represent our scene. We want images to have sufficient
uniformity in brightness and colour to not distract us too
much across channels. And we care about image
rreeggiissttrraattiioonn iissssuueess lliikkee oobbjjeecctt aalliiggnnmmeenntt aaccrroossss bblleennddss.
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IInn oouurr CChhrriissttiiee EEGGGG tthhee hhoorriizzoonn iiss tthhee ggrreeeenn lliinnee aanndd tthhee
vertical is straight ahead. Each of the red grids is 5
degrees. We don’t want edges to look broken, but
instead reasonably smooth, continuous and straight.
Geometric accuracy is important for good training. And
mmaannyy ttaasskkss rreeqquuiirree aaddeeqquuaattee FFiieelldd ooff VViieeww vveerrttiiccaallllyy aanndd
horizontally from the DEP (Design Eye Point). For all
simulators we care about Blend zone visibility and colour
convergence. If we need Night training we care about
how Black and IR light is displayed, and hence need very
llooww aammbbiieenntt lliigghhtt.
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FFoorr hhiigghh qquuaalliittyy iimmaaggeess wwee ddoonn’tt wwaanntt ttoooo mmaannyy
blemishes, dead pixels, reflections or glare, and we care
about pixel aspect ratio and shape. The light source
peaks and valleys in the spectrum may affect how natural
scenes look compared to noon sunlight or bluish dusk.
FFoorr eexxaammppllee XXeennoonn mmaayy bbee eeaassiieerr ttoo ccoolloouurr mmaattcchh tthhaann
mercury or metal halide lamps. Some but not all people
care about how warm or cold the white point is. This can
be useful for choosing which projectors are adjacent.
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WWhhoollee bbooookkss hhaavvee bbeeeenn wwrriitttteenn oonn hhooww ttoo mmeeaassuurree
these static parameters . But a few tools we recommend
for measuring Simulators are a laser total station, a
colour meter, a luminance spotmeter, digital camera and
laptop with test pattern programs like DisplayMate or
ssiimmiillaarr. FFiirrsstt lleett’ss jjuusstt tthhiinnkk aabboouutt hhooww wwee sseeee.
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WWiitthh rreeaalliittyy aass tthhee uullttiimmaattee mmooddeell oorr ggooaall,, tthhiinnkk aabboouutt wwhhaatt aa
young pilot might see looking out a window – simply
observing….what does she see? Obviously both her eyes and
her brain are the main influences...
II aamm ssuurree yyoouu kknnooww tthhee bbaassiicc ssttrruuccttuurree aanndd ccoommppoonneennttss - iitt’ss
about 25mm diameter and filled with 2 fluids of refractive index
1.336. The cornea and bi-convex lens with focal length around
20mm focus the light on her retina. Her lens changes shape to
focus between infinity and around 100mm to accommodate
ffooccuuss oonn hheerr ffoovveeaa. HHeerr iirriiss eexxppaannddss aanndd sshhrriinnkkss ffrroomm aarroouunndd
1-8mm to regulate light.