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DigiUpdate.Com |
Testing PQ on Digital
Displays:
DVI, VGA, Component, 1x1
mapping |
January 25, 2004 |
Methodology:
I downloaded the demo version of a program called
DisplayMate. Its a great program and now I intend to buy the full version. The
demo version has 6 patterns that I used for this testing. I ran the DisplayTest
program and captured each of the 6 patterns in bmp and jpg formats.
The patterns are:
|
1 |
1x1 Pixel checkerboard |
Pixel tracking and phase lock on displays. This
pattern is essential a 1 pixel black and white checkerboard board, the most
rigorous and significant one for this test. |
|
|
2 |
Vertical lines |
To check improve sharpness and horizontal resolution.
This pattern has 2 vertical bar areas - one area is a pixel alternating
black and white, whereas the second one is 2 pixel alternating black and
white. |
|
|
3 |
Grey scale text |
Grey scale testing with text |
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4 |
Grey scale rectangles |
Grey scale testing extremes |
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5 |
Circle+Rectangle |
Size and Center Screen |
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6 |
250 color blocks |
Adjusting color intensity scales. Has 25 intensity
levels of each of the 10 principal colors |
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Tests, Results and Conclusions
|
Test Number |
Set up |
Results for Each
Test Pattern and Conclusions |
|
A |
DVI, 1x1 Pixel
mapping, from PC, Using BMP Images
§
DVI
Connection from PC to Samsung DLP
§
ATI card
in 1280x720 mode
§
TV is in
TV-wide mode for 1280x720 resolution to provide 1x1 pixel mapping |
|
1: 1x1 Pixel
checkerboard |
Perfect. Can see
every pixel. Astonishing |
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2: Vertical lines
|
Perfect. Each
vertical line perfect. |
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3: Grey scale text
|
Perfect: Text is
perfectly formed |
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4: Grey scale
rectangles |
Near Perfect:
Blacks 4,8 and whites 251, 253 hard to distinguish. A
display/calibration issue |
|
5: Circle +
Rectangle |
Perfect. (The
edges are cut off due to overscan. Also a display issue.) |
|
6: 250 color
blocks |
Perfect. Each
color block has perfect even color. |
Conclusion: This
is the way to PQ nirvana. 10 out of 10
|
|
B |
VGA, 1x1 Pixel
mapping, from PC, Using BMP Images
§
VGA
Connection from PC to Samsung DLP
§
ATI card
in 1280x720 mode
§
TV is in
TV-wide mode for 1280x720 resolution to provide 1x1 pixel mapping |
|
1: 1x1 Pixel
checkerboard |
No
signs of pixels. Grey Shimmering display. |
|
2: Vertical lines
|
The 1
pixel lines on left are shimmering.
The 2 pixel lines on the right look fine. |
|
3: Grey scale text
|
Looked fine |
|
4: Grey scale
rectangles |
Near Perfect:
Blacks 4,8 and whites 251, 253 hard to distinguish. A
display/calibration issue |
|
5: Circle +
Rectangle |
Looked fine. (The
edges are cut off due to overscan. Also a display issue.) |
|
6: 250 color
blocks |
Looked fine. |
Conclusion: 8 out
of 10. VGA from PC is fine except in fine resolution.
|
|
C |
DVI, without 1x1
Pixel mapping, from PC, Using BMP Images
§
DVI
Connection from PC to Samsung DLP
§
ATI card
in 1280x720 mode
§
TV is in
PC-wide mode for less than 1280x720 resolution, picture is downscaled |
|
1: 1x1 Pixel
checkerboard |
Absolutely corrupted the pattern. Strange checkerboard. |
|
2: Vertical lines
|
Absolutely corrupted the pattern. Vertical lines in uneven sizes and
gaps |
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3: Grey scale text
|
Looked fine though
not perfect |
|
4: Grey scale
rectangles |
Looked fine though
not perfect |
|
5: Circle +
Rectangle |
Looked fine though
not perfect |
|
6: 250 color
blocks |
Looked fine though
not perfect |
Conclusion: 6 out
of 10. Not having 1x1 mapping destroys detail.
|
|
D |
DVI, 1x1 Pixel
mapping, from Bravo, had to use Jpegs because Bravo does not display BMP
§
DVI
Connection from Bravo to Samsung DLP
§
Bravo in
720p mode
§
TV is in
TV-wide mode for 1280x720 resolution to provide 1x1 pixel mapping |
|
1: 1x1 Pixel
checkerboard |
Pixel
pattern is not perfect. |
|
2: Vertical lines
|
The 1
pixel lines on left are a field of grey.
The 2 pixel lines on the right look
fine. |
|
3: Grey scale text
|
Text
is readable yet fuzzy |
|
4: Grey scale
rectangles |
Near Perfect:
Blacks 4,8 and whites 251, 253 hard to distinguish. A
display/calibration issue |
|
5: Circle +
Rectangle |
Perfect. (The
edges are cut off due to overscan. Also a display issue.) |
|
6: 250 color
blocks |
Perfect. Each
color block has perfect even color. |
Conclusion: 7 out
of 10. Bravo is not as good as the PC, even with DVI connection.
|
|
E |
Component, from
Bravo, had to use Jpegs because Bravo does not display BMP
§
Component
Connection from Bravo to Samsung DLP
§
Bravo in
480p mode - gives best component out
§
TV in wide
mode |
|
1: 1x1 Pixel
checkerboard |
Field
of grey. No pixels visible at all. |
|
2: Vertical lines
|
The 1
pixel lines on left are a field of grey. The 2 pixel lines on the right
are uneven. |
|
3: Grey scale text
|
Very
fuzzy and hard to read text |
|
4: Grey scale
rectangles |
Black
levels 4,5,12,16,20,24,28 and whites 251,253 are indistinguishable. |
|
5: Circle +
Rectangle |
Jagged
circle and rectangle. |
|
6: 250 color
blocks |
Left 4
columns of dark blacks are invisible. Uneven color in all blocks. |
Conclusion: 2 out
of 10.
|
I shall try to capture these 30 test pictures using a
digital camera. I have to make sure that I have the right photography set up
to capture it faithfully. Meanwhile, you will have to rely on my observations.
Summary Conclusions
§
If you want the ultimate in PQ, use a PC with DVI connection and
make sure you do 1x1 pixel mapping.
§
Less than perfect, yet acceptable are 1) VGA connection from PC or
2) using a Bravo with a DVI connection. The loss is primarily in fine
resolution.
§
Still acceptable, though less so, is using a DVI connection from a
PC without 1x1 pixel mapping. It destroy detail.
§
Component connection, at least from Bravo, is a dramatic drop in
picture quality. The loss is in all aspects, fine resolution and detail,
evenness of color, black levels, text sharpness - you name it.
Planned Tests
§
I would like to do this test using a component connection from a
PC, except I don't yet have a way to convert ATI output to component - any
suggestions?
§
I shall also do these tests with other test patterns --
suggestions?.
§
I shall also do these tests with actual shots from movies -
suggestions?