From Snapshots, a 3-D View
How do you describe a place? How do you express its essence to people who aren’t there?
Photosynth technology from Microsoft turns Parthenon photos into a three-dimensional world.
You use the best technology you have available.
In the beginning, there was the printed word (“Dear Queen Isabella: You gotta see this place!”). Then there was audio (“My God, it’s full of stars!”). Eventually, photos (“That’s us in Hawaii. Or is it Cape Cod?”).
Wednesday, Microsoft introduced yet another way to represent a place: Photosynth. This sophisticated technology does a simple thing. It turns a bunch of overlapping photos into a 3-D panorama.
The result, called a photosynth, is a little bit like a virtual world. You can move sideways, up or down into neighboring photos. You can turn around to look behind you. And at any time, you can zoom forward incredibly far into a photo, since it retains all of its original, multi-megapixel resolution.
Creating a photosynth is free and automatic. You visit www.photosynth.com, click to install the necessary Web browser plug-in, and start uploading your photos. (You need a Windows PC and either Internet Explorer or Firefox 3. A Mac version is under development.)
Photosynth is brought to you by a 15-person team at Microsoft Research, a division of Microsoft whose projects aren’t expected to generate income. This team hopes that the popularity of Photosynth will explode and that it will actually become a new medium. In fact, someday Microsoft hopes to design a way to connect these photosynths, eventually building a complete photographic, navigable, digital version of our real world.
In the meantime, Photosynth is a great way to visit a place before you go there, to remember a place after you’ve been there, or to show your inner sanctum to the whole world.
It’s also great for museums, galleries and anyplace else where extremely close-up inspection by the masses would be desirable, but not otherwise practical. And it doesn’t take much imagination to see how Photosynth might appeal to real-estate agents.
In a Photosynth demonstration at the annual TED conference last year, the presenter blew the crowd’s mind with a photosynth of the Notre Dame cathedral in Paris, made up of photos mined from Flickr.com. In other words, Microsoft had created a seamless, successful photosynth using hundreds of existing photos, taken by different people at different times using all kinds of cameras.
That, frankly, is a far more amazing prospect than what Photosynth is today. If using existing Web photos were an option, you could have a substantial amount of the world photosynthed already.
But for technical and legal reasons, Microsoft has backed away from that approach. Now you have to take the pictures yourself, expressly for the purpose of photosynthing.
You have to take lots and lots of overlapping pictures. Ideally, every inch of the room or space should be included in at least three photos. You stand at each corner of the room and sweep the interior, snapping away; then repeat while standing against the wall. Stand on chairs, walk to a new spot, walk up close to interesting objects.
Eventually, your photosynth is given a “synthiness” score, meaning the degree of recognizable overlap. The synthiness determines how seamlessly your 3-D panorama flows from view to view.
You can also walk completely around a stationary object, taking at least 24 photos during your circumnavigation. Later, you can rotate that object online using a doughnut-shaped scroll bar.
Once you’ve transferred the photos to your PC, you sign in to Photosynth; bizarrely, you need both a Microsoft Passport account and a Photosynth account, both free. Then you click the Create Photosynth button. Technically, your PC, not the Web site, does the analysis to knit all of those photos together, so the speed of the analysis-and-uploading process depends on your computer’s horsepower.
When it’s all over, your photosynth is live on the Web, visible for all to see. (In this version, you can’t create private photosynths.)
Amazingly, the software figures out how your photos relate, even though they’re taken at different angles, zoom amounts, exposures and so on.
It’s also amazing how, when you’re exploring the resulting photosynth, the full resolution of the original photos is available. You can zoom in, and in, and in, revealing more and more detail along the way, without ever waiting for even the biggest photo files to “load.” In one example on the Photosynth site, you start in the marbled gallery of the National Archives building in Washington — and you can zoom all the way in to the words “We the People” on the Constitution in its display case.
(This is one crucial difference between Photosynth and Apple’s QuickTime VR, which has been around for years. You can zoom in slightly in a QuickTime scene, but you can’t fly nearly infinitely into one of the component photos. Other differences: Making a QuickTime VR scene requires a special, 360-degree tripod apparatus and commercial software. And a QuickTime VR scene is rooted to one spot; you can’t freely walk through a space, as you can with Photosynth.)
So yes, it’s amazing. But in its current version (“call it beta, call it 1.0, call it whatever you want,” as the Web site puts it), Photosynth is also very frustrating.
First, synthing takes practice and patience. There’s no easy way to track whether you’ve taken enough photos to cover your space. You don’t know that you’ve failed until you’ve uploaded all the pictures and discovered blank spots or clumps of detached photos.
It’s also incredibly frustrating to navigate a photosynth. There are three ways to move around in your 3-D space: the mouse, the arrow keys or the letter keys. But what you press may not be what you get. If you press the up-arrow key, hoping to look upward, you may suddenly be teleported to a totally different part of the room. That can happen, Microsoft explains, if that other photo is the only one showing a patch of ceiling. Well, fine, but it’s totally disorienting.
At other times, you might want to scroll onto an adjoining photo — but all you get is black space and a bunch of white, dusty pixels known as the “point cloud.” That’s because Microsoft has decided that once you’ve magnified a photo enough to fill the screen, you can’t scroll to any other photo until you zoom back out. Frustrating.
These annoyances add up to the most frustrating thing of all: Photosynth’s photo-centric nature. I’ve probably made it sound like a photosynth gives you a seamless virtual environment, but it’s really not that; the component photos very much retain their “photoness.” You see their outlines flicker into view as you move your mouse around a scene. When you scroll between photos, Photosynth makes no effort to make them appear as a single image; one just fades into the next.
Finally, only one photo is ever in sharp focus at a time; neighboring photos are blurred and dimmed, which destroys the illusion of being in a virtual space.
In other words, Microsoft has designed Photosynth to be less a virtual-reality tool than a glorified slideshow, a clever way to arrange a bunch of discrete photos in space. That’s fine, but it does make photosynths less magical than they could be. Compare Photosynth’s one-photo-at-a-time focus with, say, the seamless views of a QuickTime VR scene (Google “QuickTime VR gallery” to see some), where everything is in focus as you look up, down, left, right, forward or back, as if you’re inside a giant wraparound photo.
Even so, Photosynth is wicked cool, and it will find all kinds of new uses. At the very least, it represents another milestone in the evolution of place-description technologies. Until someone comes up with brain-to-brain image sharing, that will have to do.
微軟將推出免費三維場景創建軟件
2008年08月22日13:58
微
軟(Microsoft)有點像是科技領域的通用汽車(General Motors)。當然﹐這個軟件巨頭無論是在財務狀況還是市場份額上都要比那個陷入困境的汽車製造商成功得多。不過﹐和通用汽車一樣﹐微軟的規模──員工人數已逾9萬──及其官僚體系常常讓這家公司看上去比規模較小的競爭對手谷歌(Google)和蘋果公司(Apple)更加遲鈍﹐更缺乏創新。
由於微軟的Windows Vista操作系統獲得的評論不及蘋果的Leopard平台熱烈﹐其Live Web互聯網搜索服務和谷歌的差距也不斷加大﹐近年來﹐創新性上的對比越來越鮮明。此外﹐與蘋果光滑的iPhone和谷歌即將推出的手機操作系統Android相比﹐微軟的手機軟件Windows Mobile看起來要老笨些。
不過在微軟位於華盛頓州雷德蒙德的大片園區裡﹐確實存在著創新。舉例來講﹐去年Microsoft Office進行了大膽、激進的重新設計﹐無論是在口碑方面還是商業上都大獲成功。
現在﹐微軟內部有個專門開發創新產品的“游擊隊”﹐其任務就是更快地設計出更多創新產品。該部門名為Live Labs﹐它致力於更快地把科技理論轉化成現實的、基於Web的產品。這個小組只有約125個人﹐而且還進一步分成了研究不同具體項目的若干小組。
本週﹐微軟的Live Labs將推出首個面向大眾消費者的Web服務──Photosynth。這項服務能將一個場面或是場所──比如一個畫廊或是一座建築物──的多張照片轉換成三維場景﹐讓你在Web上能有置身其中之感。
與很多照片軟件都能用若干張相片創建的二維全景照不同﹐Photosynth的產物synth是虛擬三維場景。它能讓你獲得在一個房間中四下張望、或是環顧一座建築物或一個物體時的視覺感受。你能水平或是垂直地穿越一個場景﹐還能以更高分辨率放大觀看synth裡的物體﹐比如牆上的畫。
舉例來講﹐你不僅可以看到巨石陣或威尼斯大運河的一張長長的二維圖片。你還能感覺身臨其境﹐在各處走動﹐往上看天或是向下看地﹐或是停下來更細緻地察看一塊石頭、一艘船或是一座建築物。
這類三維場景的出現已經有一段時間了﹔比如有些房地產網站用它們來虛擬展示房屋。不過Photosynth使任何人都可以用任何標準的數碼相機創建三維場景﹐甚至是利用不是特意為Photosynth而拍攝的已有圖片。你甚至還能用不同人拍的同一個地方的照片。軟件會對照片進行分析﹐找出哪些有重疊以及重疊的順序﹐然後將那些匹配的圖片轉換成虛擬三維場景。
Photosynth的設計基於微軟2006年收購的技術﹐它是完全免費的﹐而且完全基於Web﹐網站是photosynth.net（將於美東時間週四午夜推出）。在這個網站上﹐你不僅可以看到自己製作的虛擬三維場景﹐還可以看到所有其他用戶的作品。
我已經對這項服務測試了大約一週﹐雖然它有一些缺點﹐但我相信它提供了一種利用照片及分享照片的全新方法。
安裝了一個小插件後﹐你就可以在網絡瀏覽器中使用Photosynth了。目前﹐它只能在Windows操作系統下運行﹐可用的瀏覽器只有微軟的Internet Explorer及其競爭對手的Firefox。用於蘋果電腦的版本還在研發之中﹐目前在蘋果操作系統中你甚至無法看到其他人製作的synth。
當Photosynth正常工作時﹐結果令人非常滿意。不過需要一些技巧才能找到匹配良好的一組照片﹐微軟將匹配度高的照片稱為達到了synthy。理想狀況下﹐一個三維場景中的每個局部都應該在至少三張照片中有所體現﹐而且相互之間要有50%的重疊。在你上傳了照片﹐Photosynth將它們轉換成三維場景之後﹐系統會給這些照片用百分制打個分數﹐表示匹配的程度有多高。
在我的測試中﹐我用了已有的照片﹐也試過了為Photosynth而特意拍的快照。其中意大利維羅納一個廣場的照片匹配度只有38%﹐而為Photosynth專門拍攝的酒店房間照片卻有高達73%匹配度。
令我不滿意的是﹐只有在你上傳了照片並等系統將它們合併起來之後﹐Photosynth才會告訴你照片的匹配度。而這個過程在網速較慢的時候要花很長時間。如果這個服務能事先告訴你照片有多匹配就好了。還有一個不足就是﹐Photosynth沒有隱私設置。你創建的所有三維場景都能被任何一位使用Photosynth服務的用戶看到。
不過﹐總的來講﹐Photosynth是看照片、分享照片的一種令人耳目一新的新途徑﹐而且也是展現雷德蒙德仍在創新的一個鼓舞人心的跡象。
Walter S. Mossberg
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