High Resolution Screen Capture

On Wed, 22 Dec 2010 10:24:30 -0700, Jim Thompson



You sure? The printscreen key should capture exactly the pixels on
your monitor(s) to the clipboard. It will look like crap if you print
a 100 DPI screen to a 600 DPI printer, or if it gets scaled on the
same monitor to other than an integral multiple of 100% (in Photoshop,
use "actual pixels"). On my CAD machine it produces an image 5120 x
1600 pixels, which is just adequate for a 7" x 5" at 300DPI (17" x 5",
actually).

On Wed, 22 Dec 2010 12:34:21 -0500, Spehro Pefhany



I tried printing to PDF at 600dpi... looks crappy unless you zoom in.

Didn't think to use Photoshop.  "N" has that, I'll try it.
        
                                        ...Jim Thompson

I've had the same issues when trying to get screen shots for documentation.
Found it best to either maximize a window  or do an ALT PrtScreen to get
just the current window. Best to maximize the window so you get the best
resolution.

There are a few programs for screen capture that come up when searching for
    "screen capture" windows
http://www.google.com/#sclient=psy&hl=en&newwindow=1&rlz=1W1GGLL_en&q=screen+capture+windows

Jim Thompson:



It has to, since the "standard" monitor resolution is 75 DPI.

If you have a monitor 15" wide with a resolution of 1280 pixel, your screen
resolution is 85,33 pixel per inch.

You can use software tricks to reduce the "pixelation" of the image by
smoothing the border between one pixel and the next, but the resolution
will remain the same.

Or you can print it 1:1, but the dimension of the printout will be about
1/10 of the screen.

On Wed, 22 Dec 2010 10:24:30 -0700, Jim Thompson



Screen capture with Print Screen and alt-print screen are at screen
resolution, not sure why you don't see the same results.

I've always used Paint Shop Pro 4.12. It can capture the full screen, a
window, an area, and a couple of other modes, and it's pixel for pixel.

Good Luck!
Rich

On a sunny day (Wed, 22 Dec 2010 10:24:30 -0700) it happened Jim Thompson



Linux import
from Imagemagick




Yea, then why use MS.
                

If print screen has got you down, try MWSnap.
Been using it for a year or so and it works well.

<http://www.mirekw.com/winfreeware/mwsnap.html

Cheers
 

Hmm, you know what would be really cool?  A "screen shot" which actually
records GDI objects.  I suppose it would have to be driver level though.
It would allow at least some objects to be captured with unlimited
resolution (i.e., TrueType / ClearType characters), or to change the
"Theme" of the capture.

In principle, this would also allow unlimited resolution of other objects
as well (buttons, etc.), though I suppose most are described by bitmaps
anyway.

Tim

You can get the Window handles. As I understand all controls are
actually windows, at least for custom controls.
So that’s a start. Now actually getting the control objects is another
matter. But the controls can be listed, eg Excel VBA project,
So there probably is a way to do it.  Why would you want this anyway?

Merry Christmas

the print-screen button



Perhaps you're being hit by HDCP?  shut down all media players.

   Try ParaBen Sceen Capture..

On Wed, 22 Dec 2010 10:24:30 -0700, Jim Thompson



As others have alluded, screen capture simply captures the pixels on
your screen exactly as they are so the problem isn't with screen
capture, per se, it's what's done with it later.

The confusion comes from 'DPI'.  DPI has meaning to printers, as
that's how they print, but none to the display screen. By that I mean
a 1280x1024 screen is 1280x1024 whether on a 15" screen, 20" screen,
or projected to wall size and, clearly, those are different 'DPI' for
the same pixels.

However, screen capture, for obscure historical reasons, sticks 72DPI
in as a default 'to have something' but it has no 'real' meaning
since, assuming you did a full screen capture, it's simply 1280x1024
pixels.

But when you stick the capture into a program that knows it's going to
print on paper all of a sudden that default 72dpi takes on a real
meaning. It thinks you've got a 17.778" x 14.222" picture at 72DPI.
(Note that this makes absolutely no difference to displaying it on the
screen as it's still the same pixels. It's going to *paper* that's the
problem)

The simple answer is to change the DPI. In Photoshop, when you select
'new file', to then paste the capture into, change the DPI setting in
that dialogue box from the default 72 to whatever you would like, such
as 300DPI, which will magically change the 'size' to 4.267" x 3.413".
Or 600 DPI for half that size (2.133" x 1.707"). Then, when you put it
into PDF (or another 'print' program) it will think the picture is
that size with that resolution.

If it's already 'saved' somewhere with 72DPI (or something else you
would like to change) you can alter it in Photoshop with "image size."
Just turn off the "resample image" check box and it'll do the magic
size change when you alter the DPI. (If you leave resample on it
thinks you want the size to remain the same so it interpolates pixels
to 'increase' the DPI to the new value. You don't want that as you'll
still have the 18" picture, with a 'faked' increase of resolution that
has no 'real' increase to go with it, and the print program will still
need to 'scale down to fit'. It also makes a HUGE file with the
increased size of no value.)

(If you don't have Photoshop then Gimp will probably do it but I don't
have that on this machine to check the menu options. I'm sure there
are others as well.)

Note, if you're going to be resizing (after the DPI change) for print
it's better to turn off clear type, and any other 'display
enhancements', as that tends to 'fuzzy up' text, to make it more
pleasing to the eye, but that 'fuzz' doesn't generally scale as well
as crisp text. It depends on how much resizing you're doing (magazines
often erase the text and re paste it with an editor, e.g. photoshop).

Another note, changing 'DPI' in Windows display properties has no
effect on the screen capture DPI since the screen is still simply
1280x1024. That 'display DPI' is a 'logical' (as in the computing
term) fabrication to set character size, not 'resolution', which is
why it seems to be backwards. I.E. if it were really 'DPI' then 120
would be smaller type than the default 96 but it works the other way
as it's more akin to 'pixels per thing to display' than 'per inch'.
I.E., use 120 pixels instead of 96 when constructing the 'thing' and,
since 'DPI' is 'fixed' by the pixel resolution on your size screen,
that makes the 'displayed thing' bigger as it takes more pixels to
make it. Screen capture, however, will still be 1280x1024 at a dummy
default 72DPI.

If you can't be bothered working it out, here is a page that shows you
the actual DPI for screen diagonal and resolution (valid only for
square pixels).

http://members.ping.de/~sven/dpi.html

Most of my ones in current use are 100-135 DPI.

Note that Fax resolution is around 200 DPI (and that's using the
"fine" setting).

A display with 0.25mm pitch pixels is about 102 DPI.

We're still a long way from having a reasonably affordable display
(say < $2K 2010 dollars) that will show a window containing 2-page
letter or A4 spread with 600 (or even 300 DPI) color. Say 10:1 for 300
DPI and 36:1 for 600 DPI. If Moore's law holds (y= 2* ln(36)/ln(2),
right? )we could see it in another decade or so.

On Fri, 24 Dec 2010 09:17:02 -0500, Spehro Pefhany



It isn't a matter of being "bothered working it out." The point was
it's irrelevant to Windows screen capture.




If you want a preview of the future try a smartphone. My Tilt2 at
800x480 on a 3.6" screen is roughly 250 DPI and, at my age, I can
barely read 'the fine print'.

On Fri, 24 Dec 2010 16:27:45 -0600, the renowned flipper



I just stuck the link in there for those who might find it useful when
looking for a new monitor or whatever-- and btw, it's the "you" for
the reader, not you personally, so, like, chill, man.

Are you saying additional information is undesirable? What the heck
kind of engineer are you? ;-)
 



I can almost pick out individual atoms with my glasses off, but there
are limits to how close one's eyeball should be to some things.

Something of 18 x 12" dimensions or so with 250 DPI to 600 DPI would
be very nice (or bigger, provided the total number of pixels stays
about the same). My camera has a ~270 DPI LCD on it, but it's made
with a low temperature polysilicon process that probably doesn't scale
to larger displays.  With so few pixels, using those displays for
working with serious data is like trying to do precise work through
some kind of tiny window- If I wanted to be a gynecologist or
laproscopic surgeon I would have gone for one of those  professions...


Best regards,
Spehro Pefhany

On Fri, 24 Dec 2010 18:23:05 -0500, Spehro Pefhany



Don't worry. I wasn't 'upset'. It's just that DPI was the point of
confusion and talking about 'bothered to work it out' implies it has
meaning.



The kind that usually gets accused of including too much 'additional
information' ;)




I used to be like that but these days they have to be BIG atoms ;)




On the other hand, an 18" view screen would sort of defeat the 'pocket
camera' concept.

flipper:



Yes, but, apart from projectors, since bigger screens have higher
resolution, the Pixel Per Inch wiill stay about the same
 


But, for the reason above, it will stay around that 72 PPI.

Why, with a resolution so lower than for printers, the image quality seems
to be similar, i.e. not "pixellated"? The light you see from a screen is
emitted, so it tends to blend with the neighbouring pixels', while the
light from a print is reflected is reflected, with an higher contrast.

On top of that there is the fact that projections are meant to be seen from
10-20 feet, monitors from 2-3 feet, smartphones from 1 foot, and their
resolution scaled accordingly.

On Sun, 26 Dec 2010 15:16:40 +0100, "F. Bertolazzi"



The root of your point is well taken because it's obviously of little
use to have 'resolution' finer than the eye can resolve but it
actually varies quite a bit and 72DPI isn't very common (not any
more).

http://members.ping.de/~sven/dpi.html

The 'problem' is really in calling it 'DPI' as it's more correctly PPI
(pixels per inch). DPI is a term for printers and printers work
differently so the 'meaning' doesn't fit for pixel displays (more
below).




A Samsung 2343BW is 102 'DPI' and a NEC MD205MG-1 is 163 'DPI'.

The 75 'DPI' number comes from the early says. I'm not sure exactly
which was used but, for example, the old 14" 800x600 IBM monitor came
in around 75 'DPI'.




If you're using an LCD try turning off clear type and then stick your
eyeball up there like it was hand held paper.

A CRT will 'look better', for the same 'fine' resolution, because the
electron gun-phosphor mechanism 'blurs' the dots. I.E. You'll be able
to read those dern skinny character lines better because they're
'spread' wider (the electron gun can't go instantly off-on-off) and
that's what clear type does for LCDs (because LCD pixels *can* be
distinctly off-on-off)

The other reason is modern monitors are typically in the 90+ 'DPI'
range, vs the older 75 'DPI', with the higher 'DPI' at least partially
eaten up by 'clear type' to again make it 'readable'.



There are a lot of differences, due to the medium and mechanism, but
the biggest is that displays typically have 24 or 32 bit depth 'per
pixel'  but ink 'dots' do not. Print 'fakes' depth by using multiple
dots (remember half tone printing?) so it takes more 'dots per inch'
to render the 'pixel' (and depends on a lot on the printer technology
being used). For a printer you really need to know the LPI when
comparing to display pixels.

That's one reason why "DPI" doesn't translate. 'Printer Dot' <>
'Display Pixel'.

In fact, CRT displays do something similar in that a 'pixel' is really
3 (1 each red green blue 256 bit depth) 'dots' making the one 'color
pixel'.



I can't even *get* paper 3 feet away with my arms so, in addition to
the above, it would clearly need more 'DPI' to look as good as a
monitor's lower 'DPI'.

The original point was that displays and printers simply work
differently and 'DPI' doesn't directly translate from one to the
other. Displays use 'number of pixels per whole image' and printers
use DPI (dots per inch). Screen capture puts in a dummy DPI but if you
simply 'shrink' the picture size for print, so it fits on the page,
you still have a 75 DPI picture (because you simply cannot print more
DPI than the printer can print). The picture is just smaller and,
since there's the same DPI but fewer inches of them, there's no place
for those display pixels to go. You lose 'resolution'.

Changing 'size' by altering the image 'DPI' retains the 'pixels'.