måndag 8 september 2008

Using Photographs to Enhance Videos of a Static Scene

I forgot to write about this a when it appeared a month ago, I am sorry about that.
If you have not seen this already you really owe yourself to check it out, it will blow your mind.

"Using Photographs to Enhance Videos of a Static Scene" is a research project that shows a way to combine high quality photos with videos taken at the same location. The result so far is research and not available in any product but it paints a bright future. Using their method they are able to increase the resolution of the whole video clip, create high dynamic range videos and to enhance exposure. They are even able to remove objects from a scene.

Checkout the project page with the complete paper and an amazing video presentation.

When you watch you can also keep in mind that a lot of companies are working on digital cameras the combine high quality photos and videos recording. There is currently a lot of research going on into computational imaging using image recognition software together with novel hardware. For example there are already digital cameras that combine video and photo to automatically take a group photo when all have their eyes open is closing their eyes.

onsdag 30 juli 2008

Video on your web page

Are you looking to put video on your web page? Then you should take a few seconds and check out Video web wizard 2 that was released today. The program basically does everything for you, ie converting the video to flash, generating the necessary HTML code and so on.

Check out a video about video web wizard 2 here

söndag 25 maj 2008

Remove motion blur from videos

When you take move the camera while taking a photo you get motion blur. At this years Siggraph conference there are several papers about how to remove motion blur from images. Take a look at this paper High-quality Motion Deblurring from a Single Image that uses a single blurry image as source and makes a virtually perfect photo. The screenshots are quite amazing. As people from Abobe are part of the paper we can hopefully sees this as a filter in future versions of photoshop.

Using this teqnique together with a video frame capture software like fast video indexer could create really awsome screenshots from videos.

The abstract for the paper:
"We present a new algorithm for removing motion blur from a single image. Our method computes a deblurred image using a unified probabilistic model of both blur kernel estimation and unblurred image restoration. We present an analysis of the causes of common artifacts found in current deblurring methods, and then introduce several novel terms within this probabilistic model that are inspired by our analysis. These terms include a model of the spatial randomness of noise in the blurred image, as well a new local smoothness prior that reduces ringing artifacts by constraining contrast in the unblurred image wherever the blurred image exhibits low contrast. Finally, we describe an efficient optimization scheme that alternates between blur kernel estimation and unblurred image restoration until convergence. As a result of these steps, we are able to produce high quality deblurred results in low computation time. We are even able to produce results of comparable quality to techniques that require additional input images beyond a single blurry photograph, and to methods that require additional hardware."

Self animated images

Video - A series of framed images put together, one after another, to simulate motion.

Did you know you can get away with only one image and let the brain to the work of animating the image. If you make an image in the right way your brain will fool you into animating the image yourself in you head.

Siggraph is THE yearly conference on computer graphics. This year, as usual, there are a lot of interesting papers that to be presented and some of them are already beginning to leak out.

The image will look much better in fullscreen
The effect is much better if you click the image and view it as large as possible

As I develop a video software that takes videos and generates images from it a paper about Self-Animating Images got my attention. In Self-Animating Images: Illusory Motion Using Repeated Asymmetric Patterns scientists, Ming-Te Chi and Tong-Yee Lee and Yingge Qu and Tien-Tsin Wong, propose a computational method to generate self-animating images.

Even if you are normally not interested in scientific papers take a look at the pictures in it anyway. On the project page there is also a link to a pdf with more example images. Read the instructions on the page for how to best view the images.

Here is the summary from the project page:
"Illusory motion in a still image is a fascinating research topic in the study of human motion perception. Physiologists and psychologists attempted to understand this phenomenon by constructing simple, color repeated asymmetric patterns (RAP) and found several useful rules to enhance the strength of illusory motion. Based on their knowledge, we propose a computational method to generate self-animating images. First, we present an optimized RAP placement on streamlines to generate illusory motion for a given static vector field. Next, a general coloring scheme for RAP is proposed to render streamlines. Furthermore, to enhance the strength of illusion and respect the shape of the region, a smooth vector field with opposite directional flow is automatically generated given an input image. Examples generated by our method are shown to evidence the illusory effect, and the potential applications for entertainment and design purposes."

fredag 2 maj 2008

Flash is now open source

Adobe finally on the 1st of May announced that they will turn Flash and some related technologies into open source. The new open source initiative goes under the name of open screen is backed by a number of really large media and hardware companies like:
ARM, Chunghwa Telecom, Cisco, Intel, LG Electronics Inc., Marvell, Motorola, Nokia, NTT DoCoMo, Qualcomm, Samsung Electronics Co., Sony Ericsson, Toshiba and Verizon Wireless, BBC, MTV Networks, and NBC Universal.

The goal of the new open source project is to:
• Remove restrictions on use of the SWF and FLV/F4V specifications
• Publish the device porting layer APIs for Adobe Flash Player
• Publish the Adobe Flash® Cast™ protocol and the AMF protocol for robust data services
• Remove licensing fees – making next major releases of Adobe Flash Player and Adobe AIR for devices free

What this probably means is that Flash content is going to be more common in handheld devices and perhaps even in TV boxes. Wide adoption of Interactive TV is one step closer.

More specific what has been done today is that:
• The SWF file format specification is published and there is no longer a license requirement to support the Flash media format. This makes it possible to write software that support Flash on any devices without paying royalty to Adobe. You can download the Flash specification today from here
• The FLV/F4v specification is published and you can download it from here. FLV/F4V is the standard in Flash that supports Video and Audio. FLV and F4V are the de facto standard for web video today; over 75% of broadcasters who stream video on the web use these formats.

If you are a developer you can find out more about Open Screen at Adobes development page.

It is a probably a safe bet that the open screen announcement comes as a result of Microsofts huge success with its new Silverlight platform. Silverlight offers about the same functionality as Flash but with support of Microsofts mature Visual Studio tools and the .net language.

Flash as a open format can only mean good things for the future of interactive video and is really interesting in the light of W3Cs work on a video extension for the html standard.

fredag 25 april 2008

Better looking videos?

Do you want better video quality? Fix my movies is a really interesting new free web service that will help you improve the visual quality of your video files. The service is primary aimed at small video clips, for example the ones you can record with your cell phone. These types of small videos are also the ones that are in most need of improvement.

First you need to email or upload your movie to the service. You can upload directly from your cell phone which is nice. The video file size is limited to 15 Mb and the screen dimension limit is 352x288 pixels. This is less than normal TV resolution and it might sound small, but for videos shot with cell phones it’s usually more than enough.

After you have uploaded a video to the service it will automatically be processed. After a while you can download the new improved video to your computer again as ipod video, flash video or as a windows media file. You can also opt to share your videos directly with others.

The video processing does improve the image quality and reduces the typical blocky artefacts often seen in highly compressed videos.

Fix my movies also allows you to save single video frames from the video as jpeg images. Don’t expect miracles though, you will get images of higher resolution than the video frames but to call it high-res might be to stretch it a bit.

The video processing uses a sequence of images around each frame and can thus interpolate between the frames and even increase the frame-rate. This is good since cell phone videos often are recorded at a painfully low frame-rate and an increased frame-rate makes the video play smoother.

All types of video enhancement does depend on the original video quality, if you have a low quality video as source this type of service will make a huge difference. On the other hand if you start with a high resolution video source all automatic image-processing done on the video might actually reduce the quality or make it look strange. Also remember that after video processing you will in practice need to compress the video again and loose some quality.

If you want to capture video frames from high resolution movies it is better to use desktop software like FastVideoIndexer, then you save time since you don’t have to upload and download large video files. FastVideoIndexers batch video frame extraction will also save you a lot of time.

FixMyMovies is a good free service to improve the visual quality of your cell phone video clips and a good video sharing alternative, especially for small files.

torsdag 10 april 2008

Video sharing now on Flickr

As you might have heard, Flickr, one of the world’s largest photo sharing sites has finally on the 9/4 launched support for video sharing. According to Yahoo, the owner of Flickr, the site has about 46 million visitors monthly and there are more than two billion pictures shared on the site.

The new Flick video sharing is mainly aimed at sharing private videos. The great thing is that you can now share photos and videos shot with your digital camera in the same way and on the same site. Videos are limited in file size to 150mb and 90 seconds in length; this is supposedly to prevent publishing of copyrighted material, something that has been a problem on other video sharing sites like YouTube. Even though sharing of copyrighted material is a problem it is also part of the huge success of YouTube. Flickr on the other hand start from a much stronger position.

If you already have a Flickr pro account you should be able to upload videos to your account. The pro account is $25 a year and is required to add videos. Anyone with a normal Flickr account can still view videos on the site.

Videos on Flickr are placed among your photos and you can tag and Geotag videos just as you can do with photos. You can also play the videos right from the thumbnail list and searching for videos works just as it does for pictures, you can search titles and descriptions.

Flickr has a well developed programming API making it possible to use the site for videos on your site.

Videos on Flickr has so far only been around for two days but there are already a lot of interesting videos to check out:

A Great example of a video on Flickr.

A group with some of the best videos on Flickr

The video announcing video support on Flickr

How to download Flickr videos and how to capture video frames from them

onsdag 5 mars 2008

Here are a few more notes about the new video tag. The video tag is new in html 5 and w3c is still working out the details.

With the new video tag you probably want to be able to control the video from scripts, this is also something w3c is working on and will be part of the new standard. To get an idea of how the api might work you can have a look at the free ogg play Firefox plugin.
The actual html 5 draft also has many details about how the browser should handle media.

The developers of the Opera browser has developed a test version that support the new video tag with a javascript api. Read about the implementation and download a special build.

Quite recently w3c had a workshop about video on the web. There are some interesting interview videos from the conference available

Even with the new video tag in place you need a video capture software to grab preview thumbnails for you web page.

fredag 29 februari 2008

HTML standard will support video

Video on the web

Video on the web is getting more and more popular. According to a study done by comScore in July 2007, 75 percent of U.S. Internet users watched an average of three hours of online video during the month, and internet video use is still growing by the month.

Put video on a web page

When you put an image on your web page you use the simple img tag and provide a source to a jpeg/png or gif image and you can be quite sure visitors to your web site will see your image.

If you want to add video to your web page you have a little more work to do. Depending on the browser you should use the object or the embed tag, There is currently no video tag to use and you really don’t know if your visitors will be able to see your video as there is no standard video decoder you know is installed with all web browsers.

Video html tag
Now there might be changes to this situation on the way. The world wide web consortium W3C has in their HTML 5 specification added a new video tag. When this web standard eventually will be adopted by all browsers you will be able to add video to a web page using a simple html tag just as you add an image to the page.

A video tag on your web page will look something like this:

<video id="myVideo" src="videofile.ogg">Missing decoder</video>

Just as an <img> tag you use the src element to specify the file to use in the tag. Id can be used for scripting control and the text inside the video tag is displayed if there is a problem playing the video.

What this new tag does so far is simply to replace the <embed> or <object> tag with a new more natural tag. At the moment the HTML 5 working draft does not specify that all browsers have to support a standard baseline of codec. This is what the document says about codecs:

“It would be helpful for interoperability if all browsers could support the same codecs. However, there are no known codecs that satisfy all the current players: we need a codec that is known to not require per-unit or per-distributor licensing, that is compatible with the open source development model, that is of sufficient quality as to be usable, and that is not an additional submarine patent risk for large companies. This is an ongoing issue and this section will be updated once more information is available.”

Today the defacto standard web video codec is the codec supported in the Flash player but that is not open and free and therefore does not seem to satisfy the requirement. Theora is relative new format that might satisfy the requirements but it is yet fairly untested.

The w3c is working on and it is going to be very interesting to see what they will come up will. I will continue to follow the progress on this blogg.