I'm learning how to create QTVR panoramas using PTMac. I'll be posting my notes here as I figure things out in case anyone else ends up with the same questions as me.

Today's lesson: controlling the zoom feature.

If we use the default settings (Figure 1, right), we can zoom *way* in on our panorama until the viewing area is filled with unrecognizable giant blocks of color. Ideally (in my opinion), users should be able to zoom in until they see the actual-size image: one pixel in the QTVR equals one pixel in the source, or raw, image. A comparison is shown in Figure 2, below.

The left image is a partial screen grab of what it looks like when we zoom in all the way using the default setting. In the middle is a partial screen grab of the source image viewed at 100% in Photoshop. On the right is a partial screen grab of what it looks like when we zoom in all the way on the QTVR using adjusted settings. (Note: the image is crappy to begin with because the photos were accidentally taken out of focus.)

To control how much we can zoom in and out, we adjust the minimum and maximum FOV (field of view), which is given in angular degrees (360 degrees in a full circle). For now we're only worried about the minimum FOV. Decreasing the FOV is effectively zooming in. Think of your digital camera. When your camera is zoomed all the way out, you can see more of the scene: Your field of view is greater. When you zoom in, you decrease your field of you by narrowing in on the subject you're photographing.

First, we have to figure out how large our flattened source image is. In this case, my image is 3,200 pixels wide.

If we divide that by 360, that will tell us the angular resolution in pixels per degree. 3200 / 360 = 8.888.

Next we need to know the pixel width of the shortest side of our viewing window. In our case, the viewing window is 500 pixels wide and 300 pixels tall, so we'll use 300.

Divide 300 by 8.888 to get the desired minumum FOV: ~33 degrees in our example. Now we can only zoom in until we are viewing the image at actual size (Figure 2c).

This meme has been going around a while and I was recently tagged by Sara.

Four Jobs I've Had:

• Petroleum distribution engineer (I pumped gas)


• Newspaper editor (and writer, photographer, page designer, circulation manager, ...)


• Radio station manager


• Burger flipper at McD's

Four Movies I Can Watch Over and Over:

• Sneakers ("Cow mutilations are up.")


• High Fidelity


• Spirited Away


• Gattaca

Four Places I've Lived:

• Coldfoot, Alaska (Wikipedia entry)


• Sitka, Alaska


• Fairbanks, Alaska


• Atlanta, Georgia

Four TV Shows I Love:

• Lost (I'm filling out this form because I just watched an episode and don't want to go to sleep right away)


• Family Guy


• West Wing


• Sopranos

Four Places I've Vacationed:

• Hawaii


• Key West, Florida


• Winthrop, Maine


• Portland, Oregon

Four of My Favorite Dishes:

• Yellow curry


• "The special"


• Garlic smashed potatoes


• German chocolate cake

Four Sites I Visit Daily:

• UHX


• Google


• Urbanhonking


• CSOF

Four Places I Would Rather Be Right Now:

• In bed


• Portland, Oregon


• Tokyo, Japan


• London, England

Four People Who I Would Like to Read Four Things About:
If any of you follow suit, let me know and I'll link it up

• Rob


• Kyle


• Heather


• Tom

Update: Now in color and with pictures

We're now roughly 10 percent of the way through 2006, and it's time to take stock of my progress on each of my resolutions.

Zero credit card balance

Status: Behind schedule

This situation has actually gotten worse since January 1. I was making reasonable progress until I purchased a ticket to Las Vegas. That shouldn't have affected my goal too much, until it was compounded by unforseen expenses related to my recent hard drive failure.

I think I can still make this goal happen, but it comes at the expense of another. My plans for visiting Europe this fall have become abbreviated: Instead of one week in Paris and one in London, I'm planning on only spending a week in/around London.

Post one entry per week to cmerrill.com

Status: Ahead of schedule

While some may argue the merits of some of my entires, I'm currently well-ahead of schedule, averaging 1.25 entries per week. In theory, I could not write another entry for 2 more weeks and still be on track for accomplishing this goal.

Write one handwritten letter per month

Status: Behind schedule

I haven't written one yet. Since we're still early in the year, I don't anticipate any problems catching up.

Buy two new CDs per month

Status: On schedule

I bought two CDs in January: Cat Power's "The Greatest" and "Tales from Turnpike House" by Saint Etienne. I'm pleased with both selections and look forward to my next purchase. If you have any suggestions for new discs, please leave them in the comments. Keep in mind I'm trying to restrict my selection to music released in 2006, but will make exceptions.

Be able to run three miles in 25.5 minutes

Status: Way behind schedule

I don't think I've even laced up my running shoes this year.

Leave the state five times

Status: On schedule

Toward the end of January, I visited the Tennessee Aquarium in Chatanooga. I was only out of the state for a few hours, but outside the state is outside the state. Future plans include a trip to Las Vegas next month and a trip to London in the fall. That leaves two more extra-state trips to plan before the year is out.

Spend eight days in Paris London

Status: Revised

Due to financial constraints, this goal is being revised to spending eight days in London.

Read 13 books

Status: On schedule

Book No. 1 was "Blink" by Malcom Gladwell. Book No. 2 is in progress: "Don Quixote" by Miguel de Cervantes. I didn't read Amazon's description very carefully, so I was surprised when it turned out to be almost a thousand pages. I'm enjoying it so far.

Prepare/cook 21 meals per month

Status: Behind schedule

I was doing OK at the beginning of January, but have since fallen behind. I think I can catch up, though -- especially considering that accomplishing this goal means spending less money, leaving more for paying down the credit card.

Produce and upload 34 minutes of audio/video content

Status: On schedule

The video from the aquarium visit is a bit over three minutes long, which means that I've finished 10 percent of this goal and we're about 10 percent of the way through the year. It doesn't get much more on schedule than that.

Conclusion

I obviously have some catching up to do, but I'm not yet so far behind that any goal is out of reach.

Due to computer troubles, I'm effectively offline. If you send me e-mail and I don't get back to you right away, it's not because I'm ignoring you. Feel free to call or send me a text message if you need to reach me.