July 22, 2007

PowerPoint Presentations On The Zune

One of the things that I started using my Zune for within days after I bought it is PowerPoint presentations. By using pictures as slides the Zune is surprisingly effective for this task if you follow a few guidelines and best practices. Going forward I will refer to JPEG-pictures as slides but from a Zune point of view these are of course pictures.

What Makes The Zune So Great As PowerPoint Presentation Device?

Now before you scoff at this idea look at what the Zune has to offer:

  • Zune has 30 Gigs of storage space – at 100KB a slide that’s roughly 300,000 slides that fit onto it.
  • Zune has external video output – both NTSC (US) and PAL (most of Europe, Africa, Asia, Australia, parts of Southamerica), for more on NTSC/PAL check out, also most SECAM TVs (France, parts of Africa) are able to process PAL signals.
  • Zune is small and compact – sure beats lugging a notebook around.
  • Zune can play a soundtrack to your slide show – if you are good at it you could even create a presentation narrative with cues for you to move on to the next slide.

Of course there are a few areas where the Zune falls short:

  • No variable custom timings for slide shows – I would love to be able to set times per picture/slide but the Zune only has a limited set of global timings applicable to all slides, that means you’ll have to do it by hand (or keep reading further down on Custom Timings and use a workaround).
  • Zune only supports JPEG slides – but  it’s easy to work around any compression artifacts by setting the quality of these slides very high (>95%).
  • No animations (goes along with the previous bullet) – no GIF animations, however there are a few things you can do with repeating slides that can simulate some basic animations surprisingly well – of course that means your number of slides can go way up.

Open questions:

  • Nobody at Microsoft was able to tell me if the Zune’s NTSC output is compatible with some of the other NTSC standards such as NTSC-J in Japan. Same for some of the other PAL standards like South America for example.
  • I also didn’t get a definitive answer about the Zune’s screen resolution through the external video output. However after a few test pictures I am convinced that it is indeed 640 x 480 ignoring overscan (see move on that topic below.
  • Finally: sometimes the Zune displays a "Zune ring" while loading pictures, I am not sure how to supress this other than just avoiding browsing through very large JPEGs. If in doubt do a test run!

If anybody knows the answers (and has valid sources) please let me know – thanks!

The Basic Process

The idea is to create your slides in PowerPoint, save them off as JPEGs, scale them down to Zune’s 640 x 480 external resolution and then synch them to your Zune. Along each step there is room for optimizing your slides to get the best possible output on your Zune.

Designing PowerPoints For The Zune

When creating PowerPoint decks you’ll have to follow some restrictions to get good output on the Zune:

  • Font Size – Check out the font comparison slides further down, everything below 12 points becomes more guess work than reading; you’ll also notice that sans-serif fonts like Arial appear more legible. If in doubt create a test slide with the fonts you want to use!
  • Textures – Avoid objects with very small high-contrast fill-patterns, especially any kind of hatching. The resizing of the slides can lead to some ugly moiré patterns in the final output. If you do encounter moiré patterns you may try to lower the contrast of the fill-pattern, run a smooth or slight blur on the large slide before re-sizing it or best: just pick a different pattern. Things that work well are low-contrast “marble”-patterns and gradients.
  • Horizontal Lines – If you plan on using an older CRT aka tube-based TV as your Zune output device avoid 1-pixel wide high-contrast horizontal lines. Ditto for horizontal hatching patterns! Thin horizontal lines will flicker horribly due to the interlacing of these TVs. Conventional TVs will “paint” the picture onto the screen in two passes: pass 1 paints all the odd lines = 1, 3, 5… pass 2 paints all the even lines = 2, 4, 6 and so on. This painting of 2 “half-pictures” repeats 30 times a second (NTSC). Say you have a 1-pixel wide black horizontal line on white background on picture-line 127, it will get painted 30 times a second when the odd lines are drawn. During the drawing of the even lines white background gets drawn in lines 126 and 128 so effectively you’ll switch between black and white 30 times a second à welcome to flicker-central, home of the eye strain!
    Solution: make your horizontal lines wider! A 5-pixel wide line for example will have 3 lines drawn on the odd lines and 2 lines drawn on the even lines – less noticeable!
    Even better: anti-aliasing will smooth out the harsh contrast between neighboring pixels so there will be less flickering. This will more or less happen automatically when your resize your slides to the Zune resolution, see below.
  • Backgrounds – Personally I like light backgrounds, when doing a presentation on a large screen it makes the room brighter and prevents your audience from falling asleep J Well, it doesn’t matter as far as the Zune is concerned, just avoid very detailed backgrounds with high contrasts or patterns and hatchings of any kind. Dark backgrounds can look good as long as the rest of the slide is designed to go with it.

Slide with dark background, smallest font size in that slide is 14 points. This would also be a great candidate for animation: Add year for year in four animation steps.

Exporting Slides From PowerPoint

After you saved a regular.PPT or .PPTX version of your deck proceed to save your slide deck as graphics. Pick a lossless format like PNG (preferred) or TIFF (which works but usually results in bigger files than PNG), don’t use JPEG (it’s lossy), don’t use BMP (files are much bigger than needed). Then chose the “Every Slide”-option.

This is where you will run into one a problem! By default PowerPoint exports slides in a resolution of 96 dpi (960 x 720 pixels for the standard 10 x 7.5 inches page setup). Since we want to scale these down to 640 x 480 later we need higher resolutions to keep aliasing artifacts at a minimum and improve image quality. Follow Microsoft Knowledge Base article #827745 (How to change the resolution of a slide that you export as a picture in PowerPoint) and set dpi to 200.

How big is the difference between a slide resized from 960 x 720 to 640 x 480 versus 2000 x 1500 to 640 x 480?

Resized from 906 x 720 down to 640 x 480.

Resized from 2000 x 1500 down to 640 x 480, looks much better, more legible. 

Resizing The Slides

Once you have all of your slides as 2000 x 1500 PNG files you’ll have to resize them to 640 x 480 resolution and save them as high-quality JPEGs. I prefer programs that support batch processing (I am too lazy to resize 100 slides by hand) and have a Lanczos-resampling algorithm implemented. Both of these requirements are fulfilled by IrfanView. For batch processing use the /resample option and make sure the Lanczos-filter is the default in IrfanView’s .INI file (ResampleFilter=5). It is easiest to start IrfanView and bring up the “Resize/Resample Image”-dialog, make sure the Lanczos filter is selected under “Size method”, quit the program and the default is set. Same for the JPEG quality, make sure the default is set to a high number like 95%. The quality difference between 95% and 100% is very small but file size may go up by a third! On the other hand go with 100% if you really need the best possible quality.

Synching To The Zune

Make sure your slides are still named in order (Slide001, Slide002…) and add them to your synch-list in the Zune Software. Keep one directory per slide deck and make sure there is enough space on your Zune.

Tips & Tricks

Here are a few ideas on how to make your PowerPoint presentations on the Zune even better!

  • Animations – Many PowerPoints look better with a few well-placed animations! When deciding on the timing of animations keep in mind that if you want your slide deck to run unattended (in slide show mode) the smallest time interval is 3 seconds! But for manual presentations it’s basically as fast as you can press the next button.
    The most effective PowerPoint animations on the Zune are call-outs, pop-ups or significant changes in general. Unfortunately small animations will get lost in a 640 x 480 resolution. Some of my favorite animations are arrows with animated textures indicating continuous data flow – don’t try that one the Zune! First of all unless the arrows are huge the animation is too subtle and second you would have to click through 20 – 30 slides to show a good animation – yikes!
    So, stick to some big, bold animations, mostly slide components appearing and disappearing. Forget fly-ins, rotations, anything continuous, gradual, looping – too much work!
    Some good examples are: sales bar charts by quarter – animate in four slides and as you present your narrative pop-in quarter by quarter, bar by bar (take the dark Cat Food Market Share slide further up as an example). Or present a three-tier network architecture – animate the slides to show tier 1, then tier 2, then tier 3 and finally all tiers together.
  • Custom Timing – Let’s say you want to create a repeating slideshow that runs without interaction but you need custom timing for each slide. For example you want to display slide 1 for 5 seconds, slide 2 for 10 seconds, slide 3 for 5 seconds and so on. Just find the lowest common time interval needed, in this case 5 seconds and repeat slide 2 once. So your new slide deck would be: slide 1, slide 2, repeat of slide 2, slide 3. Give it a try! With Zune’s soft-blend from slide to slide you will not notice the transition from slide 2 to the repeat of slide 2.
  • Time Intervals – The other problem related to timing for unattended slide decks is Zune’s limited amount of settings available: 3, 5, 7, 10, 15 and 30 seconds.  If your slide deck is heavy on animation you’ll have to pick 3 seconds but that also means that for your non-animated slides you’ll have to insert lots of repeats! Even with 3 seconds your animations will look slow and blocky but that’s the best you can do with the slide show timings. If you want faster transitions than 3 seconds you’ll have to run the slide deck by hand. Also: even when in slide show mode you can manually jump back and forth in your deck at any time!
  • Soundtrack – The Zune is capable of playing a soundtrack while displaying your slide deck. However it’s very tricky to synch up a soundtrack to specific slides if for example you want to use sound effects with certain slides. Because you’ll have to kick off the music first, then jump back to the Pictures menu and start your slide show. So leave at least a few seconds of fade-in while you start the deck. In my opinion the whole synching is too much of a hassle but give it a try if you have lots of time. For repeating slide shows don’t forget to set your music to repeat as well, unless you have a huge playlist of different songs that lasts for hours.
  • Slide Cropping – Here is something to try with existing slide decks: try to crop as much background around the text to make it more legible. Compare the text in the slides below, it is in Arial 10 points. Much more legible in the cropped slide and I still managed to get the ASUG logo in! If you don’t want to crop each slide by hand you can use tools like IrfanView to do batch processing, use the /crop=(x,y,w,h) option.

Looks good but the last few lines are hard to read and there is a lot of wasted space around the edges.

Same information, but due to cropping the text takes up more space and is more legible.  

  • Overscan – Depending on your display device you may have to leave a little bit of buffer around your text and graphics. Many older TVs, especially CRTs from the 80ies and earlier, are pretty generous with how the image is framed on the tube. If you want to be absolutely safe on even the crappiest TV you should leave a safety margin of 24 pixels on the top and bottom and 43 pixels left and right. The remaining area is what is referred to as “Title Safe” by television broadcasters. In reality most newer TVs are usually able to display the “Action Safe” area: leave a safety margin of 17 pixels top and bottom and 21 pixels left and right. Most modern flat panel TVs don’t have this problem, most projectors are fine as well but if in doubt just use the slide below and do some test runs on your output device.

Save this PNG slide, convert it to high-quality JPEG and use it to test overscan on your video output device!


Note how poorly this big-screen TV (only about 5 years old) performs! On the left there are about 40 pixels missing, on the top it is about 30 pixels! Compare that to a commercial DLP projector:

There are only 2 - 3 pixels missing on the top and the bottom and 5 or 6 pixels left and right!


And finally: I’d love to hear from you! Please let me know any ideas on how to make PowerPoints on the Zune even better! Also I would love to showcase any PPT decks that you think works really well on the Zune, however you have to be the author and grant me free publishing rights so I can post them here.

My email: zuneppt (at)

January 16, 2007

Zune And IPod Display Comparison

OK, let's just make it official: I love my Zune!

Being a long-time iPod user I never thought something else could come along and make me give it up but... the Zune did it! Besides having a built-in radio, besides the build-in WiFi, besides the snappy user interface, the great finish (bye bye fingerprints!) and all that - what I love the most is the display!

Both are 320 x 240 but the Zune display is much nicer! It's brighter (and that's just on the medium brightness setting), it's bigger (3 inches versus 2.5) and the colors seem to be slightly better too. Although the screen shots below turned out so crappy you can't really tell, sorry.

Here is a side by side comparison of the displays

On a recent plane ride I watched some A-Team and I pity the fool who doesn't enjoy video on the Zune. Finally I can actually see stuff! I tried it on the iPod before and that display is just below the critical treshold where viewing just isn't fun! The Zune on the other hand looks very good!

OK, granted the Zune won't replace my laptop for longer video sessions but for a quick episode of "I love it when a plan comes together!" the Zune works!

These photos didn't turn out very well, in reality the colors are almost perfect with good saturation.