Problem with image export and text aliasing

  • Thread starter Thread starter Bertrand Gorge
  • Start date Start date
B

Bertrand Gorge

Hi,


I did post this problem already with no luck...

On some computers, mostly laptops as I've been able to see, there's a
bug in the image export of powerpoint.

I've been able to reproduce the problem on a recent vaio with winXp
and Powerpoint 2000, and on two very recent Dell laptops with winXP
and office XP.

Here's a sample image of what I get :

http://bertrand.famille-gorge.org/page_03.png

As you can see, the texts are not antialiased properly, to say the
least...

Note that I've played with different combinations of font smoothing in
the display control panel, and with different fonts, with absolutely
no effect. The image format is not guilty as well as png is a lossless
format...

Any thoughts ?

Bertrand Gorge
 
This is fairly typical of a low resolution PNG slide print. Have you tried
increasing the slide size using
File | Page Set-up | Then adjusting the dimensions of the slide (evenly to
maintain ratios) by doubling or tripling of both height and width.

This will increase the number of pixels that PowerPoint feels it needs to
generate. When you save to PNG, after adjusting the slide "size", you
should see cleaner, better looking PNG files.

--
Bill Dilworth, Microsoft PPT MVP
===============
Please spend a few minutes checking vestprog2@
out www.pptfaq.com This link will yahoo.
answer most of our questions, before com
you think to ask them.

Change org to com to defuse anti-spam,
ant-virus, anti-nuisance misdirection.
..
..
 
Here's a sample image of what I get :
http://bertrand.famille-gorge.org/page_03.png

As you can see, the texts are not antialiased properly, to say the
least...

Note that I've played with different combinations of font smoothing in
the display control panel, and with different fonts, with absolutely
no effect. The image format is not guilty as well as png is a lossless
format...
Click to expand...


There is indeed a bug in PowerPoint's image exports, and I'll bet it's
responsible for this. Check the master for this particular slide. I'm betting
that it's an image - an 8-bit one.

Temporarily change it to a solid color and try exporting again. My guess is
that the results will be much better.

If so, you need to convert the background image to 24-bit and re-insert it.
 
Bill Dilworth said:
This is fairly typical of a low resolution PNG slide print. Have you tried
increasing the slide size using
File | Page Set-up | Then adjusting the dimensions of the slide (evenly to
maintain ratios) by doubling or tripling of both height and width.

This will increase the number of pixels that PowerPoint feels it needs to
generate. When you save to PNG, after adjusting the slide "size", you
should see cleaner, better looking PNG files.
Click to expand...

Well it indeeds produces bigger images, but that doesn't solve the
problem: I do get perfectly clear PNG exports with this picture size
on half my computers, it's only on those laptops that the problem
occurs, whatever the resolution...

Obviously, exporting the images in 3000x2000 then stretching the image
using some kind of bicubic interpolation would probably work somehow,
but I think my clients will complain that our software is very slow
and a memorywise not very optimized...!

b. gorge
 
There is indeed a bug in PowerPoint's image exports, and I'll bet it's
responsible for this. Check the master for this particular slide. I'm betting
that it's an image - an 8-bit one.

Temporarily change it to a solid color and try exporting again. My guess is
that the results will be much better.

If so, you need to convert the background image to 24-bit and re-insert it.
Click to expand...

Tried that. I also tried no background at all, just black on white
text, with no better result...

Also note that the export works well on some PCs, and not on some
others, with various versions of windows and office... I've only been
able to reproduce the problem on laptops though (Dell latitude x300
for example).


B. Gorge
 
Tried that. I also tried no background at all, just black on white
text, with no better result...

Also note that the export works well on some PCs, and not on some
others, with various versions of windows and office... I've only been
able to reproduce the problem on laptops though (Dell latitude x300
for example).
Click to expand...

Gets weirder by the minute, doesn't it?

OK. Bill's point about image size is valid, but not in this case, I don't think.
Your sample image was at a size that should have produced far better-looking text
than what you're seeing.

The problem isn't endemic to all laptops; I use several here and haven't seen the
problem except in the case that I described earlier (8-bit b/g image).

There are problems with animated text in some situations; try removing any
animations and exporting to PNG again.

Try cutting back hardware acceleration on the affected computers.

How to set graphics hardware acceleration back
http://www.rdpslides.com/pptfaq/FAQ00129.htm

Also try changing the display settings; make sure you're set for 24 or 32-bit color
(millions of colors) modes rather than 16-bit (thousands) or 8-bit (256 colors).
 
Steve Rindsberg said:
Gets weirder by the minute, doesn't it?

OK. Bill's point about image size is valid, but not in this case, I don't think.
Your sample image was at a size that should have produced far better-looking text
than what you're seeing.

The problem isn't endemic to all laptops; I use several here and haven't seen the
problem except in the case that I described earlier (8-bit b/g image).
Click to expand...

Hopefully, or MS would have corrected the bug by now, wouldn't they ?
There are problems with animated text in some situations; try removing any
animations and exporting to PNG again.
Click to expand...

Yeah, I say those threads about animated text, but that's not the
problem here, I could reproduce the bug with a lame white slide with
only "hello world" on it...
Try cutting back hardware acceleration on the affected computers.
Click to expand...

I will try that... Though I really can't tell our clients that if they
see this problem they should change their graphic card settings
(corporate...)

Also try changing the display settings; make sure you're set for 24 or 32-bit color
(millions of colors) modes rather than 16-bit (thousands) or 8-bit (256 colors).
Click to expand...

Yes, I've toggled those as well.

Well, I've tried so many things (including exporting to wmf or emf and
converting programmatically to png), that I'm out of ideas for the
moment. I've decided I'll have an option to disable text smoothing
during powerpoing imports, no antialising is in this case better than
buggy antialiasing...!

Thanks again for all the input...!

B. Gorge
 
Recently, I purchased a new computer into which Windows XP was
installed. Prior to that, I was using Windows 98.

My problem occurs between Excel and Powerpoint. With my previous
computer, I had no problem creating a graph from data in excel and
once ready for presentation into Powerpoint, I would Copy and then
Paste Special/Picture into PPT. The excel graph's margins were always
set at 0.5 and the graph fit perfectly, squarely into the Powerpoint
frame.

Now, since using the new computer and OS, despite using the same
margins in excel (0.5) on all sides of the excel frame, when Copying
the excel graph for placement into the Powerpoint frame, Paste
Special/Picture results in the excel graph sitting as a rectangle in
the PPT frame, regardless of adjustments to the excel margins. The
only way that the resulting image in the Powerpoint frame will "square
up", taking the shape of the PPT frame, is to Paste Special/Link.

I've resorted to doing this but I'm getting driven nuts because of two
post syndromes;

1. Often, PPT will freeze up before the copying process has been
completed.

2. If I succeed in linking without a computer freeze, when opening the
PPT files at a later date the linking process sometimes freezes the
system again.

HELP!!!!!!!!!!

Fraser Evans
 
f. evans,
troubling, I can imagine. I had first thoughts about this but then had
second thoughts which may be better. Try this.

Do you have a printer installed, even if you don't have a printer
connected. PPT relies a lot on a Printer Driver being installed to do
stuff like this. I'd suggest installing a Printer driver for a Color
or B/W printer (color prefered by me). See if that cleans things up.
Let us know.

Brian
 
Hello Bertrand
Sounds like you may have given up already; if you haven't this is something you may want to take a look at. Check to see if the problematic laptops have Adobe Type Manager installed. I have run into instances where a font that is loaded by ATM competes with the fonts installed in the system folder. Also, are the fonts true type or postscript? Check the fonts folder to make sure there are not two different "flavors" of the same font installed. This can cause problems too

AmyM
 
There are problems with animated text in some situations; try removing any
Yeah, I say those threads about animated text, but that's not the
problem here, I could reproduce the bug with a lame white slide with
only "hello world" on it...
Click to expand...

I'd like to see an example of this, to see if I can repro the problem here.
If you'd like, email it to me at steve at-sign steverindsberg dot com
Remind me of the specifics in the body of the email if you would. With all the junk
going around by email, I'm just trashing attachments that don't appear to "connect" to
anything going on here. said:
I will try that... Though I really can't tell our clients that if they
see this problem they should change their graphic card settings
(corporate...)
Click to expand...

Is it happening to all of your clients as well, or is it isolated to certain laptops?
If isolated, there may not be any other choice, assuming its' a driver or hardware
problem.
 
Steve,
I would love to see this as well (if you get it). You know how to reach me.

--
Kathryn Jacobs, Microsoft PPT MVP
If this helped you, please take the time to rate the value of this post:
http://rate.affero.net/jacobskl/
Get PowerPoint answers at http://www.powerpointanswers.com
Cook anything outdoors with http://www.outdoorcook.com
Kathy is a trainer, writer, Girl Scout, and whatever else there is time for
I believe life is meant to be lived. But:
if we live without making a difference, it makes no difference that we lived
 
I'm coming in late to this conversation, but I'm wondering about one
thing...

I'd like to see Bertrand display the image full screen in a slide show,
capture it to the Clipboard, and then paste it as a new image in Photoshop
or equivalent.

That has often worked for me when other tactics fail...




Rick A.
 
I'd like to see Bertrand display the image full screen in a slide show,
capture it to the Clipboard, and then paste it as a new image in Photoshop
or equivalent.
Click to expand...

Good one. It limits your choice of resolutions, but at 1024x768 it's going to
give you more pixels than PPT's default File, Save As, PNG will.

I like it.
 
Steve Rindsberg said:
Good one. It limits your choice of resolutions, but at 1024x768 it's going to
give you more pixels than PPT's default File, Save As, PNG will.
Click to expand...

Sorry for not giving any sign of life, I've been busy resolving the
issue by other means...

Here's a page where I did post a few samples:

http://www.epistema.com/ppt/

As it comes, we found that we could reproduce the issue by applying
some service packs to WinXP (on a desktop machine). Now I'm not going
to try removing each service pack one by one, as we've been hit by
blaster recently and I'm not ready to put down the network again just
to solve the bug...

When a PC starts to show the problem, it goes for all the
presentations and all the slides, whatever the background, the shadow,
the animations, etc....

Thanks for any input !

Bertrand Gorge

NB : if MS is listening, I'll be happy to fill a bug report if one
show me where to go !
 
Bertrand Gorge said:
Good one. It limits your choice of resolutions, but at 1024x768 it's going to
give you more pixels than PPT's default File, Save As, PNG will.
Click to expand...

Sorry for not giving any sign of life, I've been busy resolving the
issue by other means...

Here's a page where I did post a few samples:

http://www.epistema.com/ppt/
[/QUOTE]

That certainly explains everything plainly enough.

For starters, I'd report it here:
Contact Microsoft: Use MSwish to request features, report problems, etc.
http://www.rdpslides.com/pptfaq/FAQ00545.htm

You probably won't get any feedback but it's a good starting point.
As it comes, we found that we could reproduce the issue by applying
some service packs to WinXP (on a desktop machine). Now I'm not going
to try removing each service pack one by one, as we've been hit by
blaster recently and I'm not ready to put down the network again just
to solve the bug...
Click to expand...

I'm not sure what else you can do to track the problem down, but if you get
motivated to beat on it some more, you could download the SPs and possibly the
blaster-specific patch, then unplug the machine from the network, back out the
patches and figure out at what point the scabrous text appears. Then apply
just the blaster patch and related security stuff.

A thought ..
 
Many years later.. I still have the same problem! Found an easy workaround. Load the ppt file into OpenOffice Impress and export the slide as image. excellent anti-aliasing!
 
Back
Top