Robert,
Are you, perhaps, seeing the difference between compressed (~100KB) and uncompressed (~12MB)? That is, Powerpoint is reporting the uncompressed size? I know both PSE2 and GraphicConverter report the size "in memory" which is the decompressed full size of the image.
Check to see if, when you save the Powerpoint file, the file size goes up by ~12MB or if it is a smaller increase after adding an image. This would indicate whether or not Powerpoint is re-compressing the images when it saves.
HTH
Kyle
Kyle,
I checked that and the PP file índeed seems to save the uncompressed file. How can I get PP to save the compressed image?
In case you’re wondering I use powerpoint of Windows 2000.
Compressed images received from others via e-mail remain as received. With other words these do not seem to be affected.
Robert
Robert, I just tried an experiment with PowerPoint 97. I opened a new blank presentation and inserted a Picture from file – in this case, a Save for Web image that’s 800×600 pixels and 110 kb in size. It nicely filled the page, and I saved the presentation. Then I went and checked on the properties of the saved PP presentation: XP says its size is 146 kb (160kb on disk, whatever that means). I attribute the modest run-up in size to PowerPoint overhead. I did it a second time, putting three different pictures (110,114 and 189 kb) on successive pages; size of saved PowerPoint is now 425 kb, pretty close to the sum of the three pix – very little overhead.
Not sure why later version of PP would do that differently….?
Chuck
Robert, here’s a guess:
PowerPoint 2000 apparently has enhanced tools for picture editing: contrast, brightness, cropping, recoloring, etc. Perhaps, therefore, it doesn’t save the individual pictures in their original format but rather saves an uncompressed version…? 97, with its less powerful tool set, seems to just keep the original JPEGs intact.
I’m going to look some more in the Microsoft Knowledgebase…
Chuck
Perhaps a little explanation might work here. JPG is NOT a compressed image in bytes when viewed. For an image to view or print, it has to have full pixels. Only when the image is closed and stored is the file in bytes compressed.The image format (JPG) reverses the algorithm of compression when opened (or placed in another program such as PowerPoint) much in the same way that a dried faux sponge pad is far smaller than when useable and water is applied. To get the sponge back to small physical size again (but now not useable), it’s dried (algorithm applied). The only way to get the images within a program to have less bytes is to have that whole document compressed. Those programs DO NOT recompress images individually, otherwise they’d have to have Scripts (or Actions) which would work the compression and placement of each image and that programing would defeat the image compression itself in most cases. However compression of the total document is possible (such as a ZIP) which uses an entirely different method of compression. Hope this helps a bit in understanding compression. Note the size of a JPG file when closed (PC or MAC) and stored in a folder. Now open that same file in Elements and with it selected (click on it’s title bar), go to Image, Resize, Image Size and note the filesize in bytes. It’ll be far larger than the stored file because it’s no longer compressed (the sponge has been wetted) until once again Saved. It’s also not the same file. If you do NOT save it, just X it, the original File stays as it was, in compressed state. That, of course, you can’t do with a sponge<g>.
Bob
Bob, I hear you….but apparently in PP 97 the images are saved in some way as the original JPEGs and only uncompressed when the presentation is opened. Otherwise, I’d expect the saved presentation to explode to TIFF-size and the file to become huge – which is what Robert is seeing in his version of PowerPoint and I most assuredly am not seeing in 97. PowerPoint must maintain some individual picture integrity, or you wouldn’t be able to remove them individually when editing a previously saved presentation. Obviously, I have no clue what’s happening within the code of PP, but can only report on the results.
Chuck
Chuck,
I have, but haven’t used latest versions of PowerPoint, so I’m not sure how it works compression, but it could be using linked and not embedded files also. This would work, as there certainly are programs that will do that and inflate compressed files just fine. Therefore if images are linked instead of embedded, the original JPGs would have to be stored along with the PP file so the link could be established when called upon by the PP document. This makes the PP file pretty small itself and possibly compressed by it’s own algorithm as well.
Bob
Bob, thanks. I need to read about linked vs. embedded a little more in my PP book. I thought that Insert Picture from File would embed, but perhaps it links. After I get home from work I’ll play around with that…
Chuck
Chuck,
I’d guess that the default would be to embedd the image. If it allows for linked only, that would be a "choice" option, if anything, with most programs.
Bob
I use PP 2000.
Generally, the PP file itself will be a little *smaller* than the JPEG file you’ve embedded (as the .ppt format has it’s own slight compression algorithm, somewhat like .psd in Photoshop).
Make sure you have Fast Save turned OFF.
This will make a .ppt file increase size in a hurry, as it saves incremental changes also, or some such (never have understood it, but it’s a Bad Thing).
Mac
wrote …
I selected some images by reducing these via the Save for the Web route.
The images are now all around 100 Kb or less.
However after having inserted them in the power point presentation these
images seem to have returned to their "normal" size of sometimes 12 Mb.
I feel that I am doing something wrong, but what?
I tried something similar with PSE 2 and PPT 2000. This did not happen with my file.
What settings are you using with PSE (save for web), and are you manipulating the graphic in PPT?
Ed
Thank you all for your comments and for assuming that I am as much of a wizz kid as you all are. .-)
What I understood is that in PP an image comes up as uncompressed hence the large file when saving.
Ed is saying that he has PSE and PP and that it does not occur to his file nor does this happen with Chuck’s in PP97.
So something must be done differently by me.
My thought is that I may have to save the file in "save for web" as a bitmap or psd instead of leaving it as a JPG or TIFF.
I will try and come back with a result.
Robert
Right,
I created an image as a bitmap but that went totally wrong. PP didn’t recognise the bitmap.
Then I went back to Save for Web and reduced the quality of the image to nearly nothing (i.e. 25Kb), then did a save. This time the amount of the image had been reduced from 12,1 to 2,3 Mb.
Whilst typing this I believe I have solved it. So far I have been reducing only the file size of the image but left the image dimensions uncahgned except for the last one. I will now try and reduce file size ánd dimensions. I have a feeling that that would reduce Mb’s considerably.
Robert
For projection (or onscreen) purposes, you don’t need anything over 1024 pixels wide for PowerPoint unless you have a projector that does higher than 1024×768.
Mac
Robert, an 800×600 fills most of a slide the way my PP97 is configured; I don’t even have to mess with the corner handles for pictures of those dimensions in landscape (horizontal long) mode.
Chuck
Put your screen at 1024×768 though, and you’ll see that image suffer compared to one that’s 1024 to begin with.
Same for projection.
Just a hint,
Mac
Mac, not sure what you’re saying on this one; my screen res is 1024×768 and an image that size covers the whole slide and has to be downsized either by manipulating the handles or doing a Format>Picture. Guess it depends on whether you want a border or not…. When using PP, I’m usually adding some text; for a full-screen presentation, I enjoy the simplicity of Elements PDF slide show.
Chuck, my point is, make a 1024 image and an 800 image.
(make sure they are downsized from something larger so quality is there).
Put both images in separate PP slides and change back and forth. You’ll see the 1024 one is of significantly better quality.
Point being that at 1024 display or projection, an 800 pixel image does not hit the min quality threshold for the display/projection.
Mac
Hmmm – I’m having trouble thinking that one through…will the projector show more pixels than appear on my screen? If I have a 1024×768 screen, a 1024×768 image is the most I can show in Slide Show mode; when I use an 800×600 picture, I have a white border of 112 pixels on left and right, 83 pixels on top and bottom and the image takes the rest. But every pixel is still ‘spoken for’….. I certainly agree that if I expand the 800×600 to fill the screen the quality will be less than if I had used the 1024×768 to begin with, but if the images are projected at different sizes….? I’m missing something….
Chuck
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Chuck, if I put an image in PP, using total width of the PP "slide", when I view it in slide show mode, it goes totally edge to edge of my monitor (which happens to be 1024 pixels wide).
I see a significant quality diff with same image sized to 1024 or 800. Same quality diff if projected on 800×600 projector.
If only seen onscreen at 800 or projected at 800, no real diff.
Just try it with two images, make sure they fill the PowerPoint viewable area, at least width-wize.
How could it be otherwise? The 1024 image is spanning 1024 pixels onscreen or projected. The 800 image is spanning the same 1024 pixels.
Same principle as printing, really.
I don’t understand your 112 pixel "border" in slide show mode, though. If you fill the PP frame, any image will go all the way to edge of monitor (or projector). Unless you have monitor that "wastes" some area all around the bezel, IOW doesn’t stretch all the way to edge of the bezel.
Mac
Mac, I agree with what you’re saying; I would use something less than full monitor resolution only if the image is going to be a less-than-full part of the slide (i.e. text appears in the some of the white area not covered by the image). My ‘border’ is that area I want to show white on the projected image; 1024-800=224, 224/2=112 on each side; 768-600=168, 168/2=84 top and bottom. Basically, I’m putting a small picture on a large canvas…
Chuck
Chuck and Mac,
Firstly to my main problem. I have reduced both size and quality of the image I want to display and the number of bytes has now come down to below 1 Mb. For the moment that is an acceptable size to live with.
Secondly, whilst reducing the size of the image ánd the quality I ran into the problem you both are discussing, namely the quality of the image on display. I follow Mac’s reasoning that the image of 1024 by 1024 pixels covers the whole screen and therefore the whole displayed screen on the wall or where ever. Yes there is a possibility that you will see pixels if the quality it too low.
The images I want to display will be copied into a presentation and cover only a fraction of the total PP screen as there is text beside it. So the audience will see small images. What I am now hoping for is that I am able to reduce the iamges to the desired size whilst maintaining an acceptable amount of pixels = quality. Nothing is worse than distracting your audience by showing them pixelated images.
Thank you for your help.
Robert
wrote in message…
Firstly to my main problem. I have reduced both size and quality of the
image I want to display and the number of bytes has now come down to below 1 Mb. For the moment that is an acceptable size to live with.
Secondly, whilst reducing the size of the image ánd the quality I ran into
the problem you both are discussing, namely the quality of the image on display. I follow Mac’s reasoning that the image of 1024 by 1024 pixels covers the whole screen and therefore the whole displayed screen on the wall or where ever. Yes there is a possibility that you will see pixels if the quality it too low.
The images I want to display will be copied into a presentation and cover
only a fraction of the total PP screen as there is text beside it. So the audience will see small images. What I am now hoping for is that I am able to reduce the iamges to the desired size whilst maintaining an acceptable amount of pixels = quality. Nothing is worse than distracting your audience by showing them pixelated images.
A few things are happening. Your intitial image is very large. For instance, you say the original is 12MB. I’m not sure why your file is so large. What are the pixel dimensions?
This is what I did with a test image of 2048 x 1536 pixels, 1.2MB JPG file (from a 3MP digital camera.) I am sure that you are working with something similar. Where does your original file come from, and what format is it?
I made two JPG’s, using PSE "save for web." Then I made 2 PPT files, and used "insert from file" to import to a separate PPT file. My results:
Image #1
1024 pixels (50% of original, HIGH JPG)
JPG – 137K
PPT – 173K
Image #2
512 pixels (25% of original, HIGH JPG)
JPG – 40K
PPT – 75K
If I read your posts correctly, you are saving LOW quality JPG, which adds noticeable pixelation at 100%. I have read your posts, and I’m still not sure what you do to the picture in PPT.
To make this simple, take your original image, save for web as JPG LOW, reducing to a % that gives you 1024 pixels width. Insert this file to PPT, and right-click on the image. Select"Format Picture" and then click on the "Size" tab. Change the percentage to 50%, and I believe that you will see an improvement, and the size of this picture will allow placement of text as you describe.
The pixellation you see is coming from JPG compression, and you will have to live with some if you want smaller file sizes.
Ed
Robert, note that with a PP presentation, either on computer monitor or projected with video projector, only the pixel dimensions are pertinent. Just like any onscreen or web image, PPI has no meaning here.
Trust me, if using a full "slide" width image in PP, 1024 width is ample (let the other dimension fall whereever (the max vert. dimension is not 1024 but 768).
If using, as you mention, smaller images than that, you can get away with even less. Just figure your % of full width and reduce the pixel size proportionally.
Actually, though, just for simplicity, 1024 is okay for everything, as medium quality JPEG from Elements for 1024×768 is going to be 80-120K in general, certainly no particular burden on a modern laptop.
(note however, that if you ever need quality prints or 35mm slide output from your PP presentation, these images are not large enough for good output. Many pro road warriors have two versions of their .ppt files, one for print/35mm output, and one for on screen/projection use.)
Mac
Ed and Mac,
Thank you for your information. Quite a bit of technical information to take in.
But I can lift one mistery already. The 12 Mb file is a normal jpg file I worked on with PE2. I must have added something and did some sharpening. All this amounted to the 12 Mb.
I am pressing on with my presentation as per my last message. I know that it is probably a clumsy way of doing it, but I need to get the bones of it finished by tomorrow as then people are coming over to discuss the concept presentation. The whole presentation is currently 75 MB large; a lot of images have been added and also did some fancy lay out with an inserted image. The marvels of technology make it all possible.
To come back to both your advice. I will try this during the coming week as my way of doing things is pretty pre-historic. I will come back to this thread after I tried the better ways.
Thank you for your help.
Robert
Robert, I don’t think it’s possible to have JPEG that large with pixel dimensions of 1024×768. As a matter of fact, I’m sure it isn’t. The largest JPEG image I get from my camera is something like 2 or 3 MB, and that’s at a resolution of 3072×2048; as JPEG doesn’t support layers, even editing can’t make it bigger. I guess if you’re starting with a scanned picture at high scanner resolution and save it at the lowest compression setting, you could get something larger – but not that large…
As Yul Brynner said in "The King and I"…."Tis a puzzlement!!"
Chuck
Chuck,
That thought had not even crossed my mind as it didn’t pose a problem to me untill this power point presentation popped up. I’ll double check.
Robert
The largest JPEG I can make at 1024×768 is under 900k.
And this at highest quality, setting 12 in PhotoShop.
This is size on disk, of course. Elements will report a much larger size if opened therin, as it reports uncompressed size, ala TIFF.
Mac
