For PowerPoint Viewer, keep ppt small

[Mitch Gallant]

As I've discussed in other threads here, there is a difference in how
PowerPoint Viewer (2003) handles large images compared to PowerPoint itself.
Not sure why that is, perhaps that PowerPoint pre-caches all images for
editing or something but PPT Viewer slows down dramatically for larger
presentations (say over 10 Mb). The difference might be the implementation
of one of the dlls included along with pptview.exe in the PresentationCD
folder exported by PPT.

So make sure you downsize your images (using advice in many other threads in
this group) so that your PPT presentation (or pps) is less than 5 Mb and
will behave properly in PPT Viewer 2003.

- Mitch Gallant
MVP Security

 

[Guest]

Hi Mitch

Would you try an experiment for me.

With a file with several jpegs inserted at a "sensible" resolution (ie
pretty much as small as the file will go)

Try to cut each picture in turn and paste it back "paste special as a jpg".
Then resave with a new name and compare file sizes.

For me this gives a substantial file size reduction and I'd like to know if
its general. I was originally working with very bloated files but for me it
seems to work on alreadt smallish files. Maybe you could email me results
address in profile.
--

 

[Mitch Gallant]

OK will try this and report back soon.

 

[Mitch Gallant]

John,

I have tried this on a ppt presentation with about 15 embedded jpg images
using "Cut, Paste Special as jpg" as you requested:

Original ppt Size: 2.83 Mb
New ppt Size: 1.52 Mb (after Paste Special ..)

So indeed I have verified what you have found.
I went a bit further:
I compared the Cut images by pasting into Microsoft Photo Editor and
compared the actual images in the two ppt, and indeed the images are smaller
in the "Paste Special as jpg" modified document.
So clearly "Paste Special as jpg" does some sort of intelligent (or buggy?)
image resizing on pasting.

typical example of downsizing: 940x768 ---> 824x673 (after Paste
special).

Of course I didn't try Paste Special more than once .. maybe we can reduce
the doc size down to zero!
and defy the 2nd law of Thermodynamics ;-)

A word about image quality on Paste Special ... I didn't notice any obvious
visible reduction in quality with Paste Special as JPG downsizing so this
seems like a useful tidbit to know and document.

Would be interested to know if this downsizing for Paste Special is by
design and what the algorithm for resizing is.

Cheers and nice find!

- Mitch Gallant
MVP Security
www.jensign.com

 

[Steve Rindsberg]

So clearly "Paste Special as jpg" does some sort of intelligent (or buggy?)
image resizing on pasting.

Not so mysterious.

If the shape you copy occupies the full 10" wide slide, you get a 960 pixel
image back, at least in PPT2003. Or fewer pixels if the original shape you
copy sprawls over less screen real estate.

A word about image quality on Paste Special ... I didn't notice any obvious
visible reduction in quality with Paste Special as JPG downsizing so this
seems like a useful tidbit to know and document.

Since it gives you back approximately what you already see on screen, you won't
generally see a big quality difference.

OTOH, if you reduce a big image to a postage stamp on the slide, then do the
copy/paste special/jpg dance on its head, I wouldn't plan on bumping the image
back up to full slide size. Not if you have your glasses on. ;-)

 

[Mitch Gallant]

I think the point is that when the Insert image from file, you get the
entire image included in the ppt file.
If you Paste special as jpg, it resizes on import as you say (I think) which
was surprising and mysterious to me.
(and some others I expect
- Mitch

 

[Steve Rindsberg]

I think the point is that when the Insert image from file, you get the
entire image included in the ppt file.
If you Paste special as jpg, it resizes on import as you say (I think) which
was surprising and mysterious to me.

It doesn't resize anything so much as it gives you what you asked for. You
just have to be able to read the menu. Which isn't written in the clearest
English, hence the mysteries.

See, when you copy, PowerPoint (or any app) can put all kinds of different
representations of the copied item on the clipboard. PowerPoint copies the
image *as displayed*, the image as an MS Drawing Object and several other
formats. When you choose As JPG, PNG or GIF, the image *as displayed* is what
you get.

A normal Paste, Nothin' Special, gives you the MS Drawing Object (in the case
of an image, you get the original, full size).

 

[Mitch Gallant]

Thanks Steve. That explains it nicely.
Another question:
When you Insert Picture from file (or Paste I guess) what determines how
that image is sized in the slide?
It definitely is not the actual size of the image (but the entire image is
embedded in the ppt).
- Mitch

 

[Mitch Gallant]

OK strike that last comment. I was looking at a 600 dpi image and 2484
pixels wide so was only 4" wide. I was a bit confused at first because I was
looking at this in PhotoEditor which displays size based on pixel width so
it looked huge.
Indeed, PowerPoint initially displays the actual width (in inches) of the
image.
Also, the "Reset" button doesn't show the change back to actual size unless
Preview or OK is pressed.

- Mitch

 

[Austin Myers]

Mitch,

Not quite certain why your seeing this as I've put together Pressies in the
75 meg range and played them with the viewer fine.


Austin Myers
MS PowerPoint MVP Team

Provider of PFCMedia http://www.pfcmedia.com

 

[Mitch Gallant]

hmmm I haven't had time to go through ever aspect of the large ppt I had
been handed.
Most of the images were 600 dpi hi-res scans (~ 5000 pixel dimensions)
including the SlideMaster bgnd image.
As I said before, I downsized all the images and the problem with PP Viewer
2003 went away.
Also I mentioned that there was a huge difference between the viewer and PPT
2003 itself (on 2 different machines).
- Mitch

 

[Austin Myers]

Weird because I just haven't seen it happen.


Austin Myers
MS PowerPoint MVP Team

Provider of PFCMedia http://www.pfcmedia.com

 

[Steve Rindsberg]

OK strike that last comment. I was looking at a 600 dpi image and 2484
pixels wide so was only 4" wide. I was a bit confused at first because I was
looking at this in PhotoEditor which displays size based on pixel width so
it looked huge.
Indeed, PowerPoint initially displays the actual width (in inches) of the
image.

Yes and no. An image is, at heart, a collection of numbers that represent the
colors that each pixel in the image should be when it's displayed on some
output device.

How big is a number? That times the number of pixels in the image will give
you its width or height in inches.

Silly question, right?

The point is that images have no height or width as such. They take on
physical dimensions only when they're realized on physical devices, but since
the software and users that run the devices might make the images any old size
they like, that doesn't tell us much either.

Because it's sometimes convenient to be able to specify in advance that "The
PROPER size for this image is 5 inches wide" some image formats, TIF for
example, allow for including height, width and dpi.

This doesn't affect the image itself, it simply acts as a suggestion to the
software that imports the image. And the only difference between two TIFs of
the same image, one saved at 600 dpi and the other at 60 dpi is the few bytes
that hold the height/width/dpi values. The pixels are the same.

If the image format includes suggested dimensions, PPT will generally try to
respect them.

Not all image formats provide for storing even these suggested dimensions.
PowerPoint still has to make the images SOME size when it imports them, so what
size should it be? Well, what does it know about the image? Pixels across and
down. So it uses a somewhat arbitrary number (like exports, it varies between
versions and OS settings but usually from 72 to 120 dpi). Divide number of
pixels by "magic" number of pixels (dots) per inch and voila, inches.

Are we totally confused yet or should I explain some more?

 

[Steve Rindsberg]

hmmm I haven't had time to go through ever aspect of the large ppt I had
been handed.
Most of the images were 600 dpi hi-res scans (~ 5000 pixel dimensions)
including the SlideMaster bgnd image.

I'm guessing that a presentation with a few very very large images would behave
quite differently from a presentation with lots of medium or small images, even
though the size of the file is identical.

That might explain the diff between what Austin's mentioned and what you're
seeing.

Still doesn't explain the diff between viewer and PPT, but ISTR that the viewer
doesn't push very hard at the video driver, where PPT may.

 

[Mitch Gallant]

This doesn't affect the image itself, it simply acts as a suggestion to
the
software that imports the image. And the only difference between two TIFs
of
the same image, one saved at 600 dpi and the other at 60 dpi is the few
bytes
that hold the height/width/dpi values. The pixels are the same.

Yup .. I realize this ... the display software determines how the info is
presented..
but the resolution of course determines the detail .. so 600 dpi scanner
grabs finer detail than 60 dpi.
I understand what you are saying tho. Some of the process is scaling .. some
is detail.
- Mitch

 

[Mitch Gallant]

The relevant data is pixel width and height. I agree ...
But when an image is scanned .. real physical size (say in inches) has a
very real meaning because it determines what physical size is physically
scanned for image data.
Including this data in the file allows for print media to "know" about
oriignal image size for resizing etc..

For electronic display, when it is displayed by Java or PowerPoint .. the
metrical size (inches or cm) has more to do with the display scaling ..
- Mitch

 

[Steve Rindsberg]

Yup .. I realize this ... the display software determines how the info is
presented..
but the resolution of course determines the detail .. so 600 dpi scanner
grabs finer detail than 60 dpi.

And a 600dpi printer prints finer detail than a 300dpi one. But in both cases
we're talking about physical/device dots, not the numbers in an image.

But it's fair to say that a 10" original scanned at 600 dpi will present a more
detailed image than one scanned at 60dpi. But I could take the resulting
images and hand them back to you with the embedded DPI info changed. You could
have a 60dpi image with ten times the detail of a 600dpi one. ;-)

 

[Steve Rindsberg]

The relevant data is pixel width and height. I agree ...
But when an image is scanned .. real physical size (say in inches) has a
very real meaning because it determines what physical size is physically
scanned for image data.
Including this data in the file allows for print media to "know" about
oriignal image size for resizing etc..

Yup. As I mentioned there are very good reasons to maintain the convenient
fiction that an image on disk has a dpi value that means something. ;-)