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Help with "Jaggies" On Edge Detail


smacbutch

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Putting my first show together for this weekend using my new Dell 2300 MP projector. Most of the images look good on the screen, but the edge detail, for example on skiers ski poles shows "Jaggies", that is to say the pole doesn't project as being straight. I though possibly I was using to high a setting with USM, but I have only applied: Amt 110, Radius .8, Threshold 6.

All my images were taken with Canon 20D, only minor adjustments of levels and curves in PSCS, and converted all images to sRGB and that is what projector is set to.

This is my first post and have already learned a bunch from this exceptionally informative board.

Any help appreciated, wonder what other folks setting are in regard to Unsharpmask Filter & thanks a bunch.

Scott MacButch

Pocatello, ID

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Scott

Is your projector set for a resolution of 1024 by 768 pixels or higher. If it is set at 800 by 600 that may not be helping.

Are you resizing your images too small or compressing them too much. Try cropping to a resolution of 1024*768 @ 72 ppi and save them as a jpeg at compression 6.

Hope that helps

Barry

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Thanks for all the help. Went back and did a proper search on "jaggies" and pixelization. After trying about everything under the sun. I still don't have very sharply defined edges and the "jaggies" are still quite apparent when viewed on my new Dell 2300MP which the literature claims is a true XGA, 1024 x 786 pixels.

Just to review my workflow, I shoot my Canon 20D images in raw format, convert in Breeze Browser, most only require small amount of Levels and/or Curves, small amount of USM.

I swith the color profile from Adobe 1998 to sRGB

Then I have been just resizing the horizontals longest side to 1000 pixels, let the short side fall where it may with normal boxes checked: constrain proportions & resampling with Bicubic Smoother.

As advised I'm creating jpegs of quality 6 which give me roughly a 190K jpeg.

The Dell is set up as follows:

Analog RGB 1600 x 1200/60 Hz

Aspect ratio 1:1

Video Mode sRGB

The images projected are not bad, just thought for a $1,000 DLP projector that my skiers ski poles would be straight, and "jaggie/artifact" free, as they are when viewed on my computer monitor.

Oh well, possibly this is as good as it gets?

Thanks again for any tips,

Scott MacButch

Pocatello, ID

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Scott,

It sounds like you may be using an SVGA projector (native resolution only 800x600 px). You will likely see jaggies at that resolution. If so, you should invest in the next size up (XGA, at 1024x768 px), and size your images as 1024 px on the longest side. Even at XGA you may notice jaggies for certain high-contrast images or text, but most of the images should be pretty clean.

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  • 1 month later...

I read, with great interest, Alrobin's and bbdigital's comments on projecting PTE slideshows. As I'm considering going up this route too, I'd like to hear what model of projectors are you using.

I'm pretty disappointed with the picture quality obtained when making DVD Video using Nero 6.6 - Shimmering, lack of contrast and general fuzziness. BUT, before taking this, somewhat expensive step, I want to try one more thing: hook up my PC, via TV out, to my TV receiver.

If this works it could be a better solution, for my needs, particularly with HDTV starting next year (in the UK)

Whatever, it would certainly be a proposal, easier to get though "higher management"!

If anyone has tried this already, I'd be grateful to hear the results.

John

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Oh boy I must be pretty dense. Never thought to change the resolution on my laptop. Once I changed that to 1024 x 768 pretty much all my "jaggies" are gone.

Yes, it helps very much to match the projection resolution to the native size, otherwise you're dealing with on the fly resampling which can often introduce unwanted artifacts.

The problem is that many today use high resolution screens to display their executable slide shows and when displaying a 1024x768 slideshow at high screen resolution one either has a postage stamp sized image for the slideshow or the program must upsample from a native 1024x768 to whatever it takes to fill the screen. Neither are satisfactory solutions in most cases.

Our solution has been to duplicate the slideshow executables using higher resolution originals for the executable for screen display and 1024x768 or 800x600 (whatever the projector's native display size) for the projector. It's really quite easy to do using a freeware program such as IrfanView where you can batch resample and at the same time apply sharpening, etc., as necessary. Then create a menu on your CD and call the appropriate show.

Lin

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Our solution has been to duplicate the slideshow executables using higher resolution originals for the executable for screen display

Lin,

if you were preparing images for display on, say, a 42" HDTV; what order of resolution would be appropriate?

John

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Lin,

if you were preparing images for display on, say, a 42" HDTV; what order of resolution would be appropriate?

John

Hi John,

That's a tough one and the answer may depend on the actual display screen being used. The "standard" for HDTV allows for approximately a two megapixel display, but the actual screen being used may be progressive or interlaced. If interlaced, this "resolution" at broadcast is divided into interlaced scan lines each of about a megapixel. If the screen being used is an LCD type I would try to match the actual resoluion of the display type itself which could be variously up to 1024 by 1024 but with the wide screen aspect probably 1024x768 would work well.

I would think experimentation might be the best way to decide in this case. Standardized DVD output at the highest resolution usually works pretty well on most of our customer's screens whether CRT type or LCD but if the display "allows" for input of a computer executable we find 1024x768 works pretty well for us.

Lin

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Lin, thank you for that. I have always, in the past, created my .exe slideshows from files 1024widex786max. (For landscape shots) and 786high for portrait aspect. Generally, and if it is necessary, filling in the rectangle with a background of gradient greys to make a 1024x786px "slide". I'm planning to do a test, in the new year, using my son's HDTV to see if there is sufficient improvement to warrant the investment in a TV upgrade.

Will post the results idc.

John

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  • 2 weeks later...

Dont know if this will help, but, found a download called QIMAGE the other day a trial version. It has the capabilities of reducing, if not erasing jaggies and pixelation, Its is in essence a printing software that has a facility for slide show enhancment by the looks of it. havenot had time to check ii fully yet. but looks promising.

Dave :unsure::)

www.ddisoftware.com/qimage

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