video back ground modifier

[heimannm]

Hi to all experts I need a video back ground modifier and video back creators software.
Please suggest me that how to change characters background in a video.

[djr33]

Can you explain what this is for? Is this for a website? Are these real people from a video camera or is it a cartoon (for example, using Flash)?
This is probably not the correct place to ask because this forum is about web design, not about video production. Of course there are many other websites that can help you with video production.

However, I do both web design and video production, so I can at least give you a basic answer.

If you want to replace any background and the video has not been made specifically for the purpose of background replacement, the short answer is that it cannot be done. The long answer is that through a technique known as rotoscoping (and masking, but complex masking) an expert FX artist can do this, but it is not easy and it is very slow. The process involves painting on every frame. In this case, the "painting" is just drawing a digital boundary to separate the foreground from the background. Then a new background can be used. Finally, to merge everything together, compositing is required, a process of blending elements. Experts can do this well, but it is not easy. Sometimes it may work out well without much work, but a lot of the time it will look very bad if it is not done by an experienced artist, usually because the colors don't match correctly on all of the borders. Note that choosing a good background is one of the main ways to make this easier and to make it look better.

A simple version, if you intend to just modify the background, is called matte painting or just mattes. This involves inserting something on top of the image. For example, if you have a video of people on a hill, then you could create a digital castle (or use a real image of a castle) and place it on top of that hill. However, if the foreground ever crosses the matte (if the people walk in front of the castle, in this example), then you will need to use rotoscoping to fix it. It's still easier than a full background replacement though.

The other option is to plan this while making the video and use a technique called greenscreen or bluescreen, also known as keying. Film someone on a colored background, then tell the computer to remove that color. Then the computer can automatically remove the background and you can insert any color you'd like. Of course this is more difficult to film, but much easier (and probably cheaper) than skipping that and trying to "fix it in post" (the term for using special FX to fix videos).


The options above are what are used professionally in the film industry and achieve high quality results.

There's one more option that usually does not achieve high quality results but can give at least a basic background replacement effect. It's called a difference matte, and the idea is that you show the computer a certain picture, and it removes anything similar to that in other pictures. This is usually messy, but if done right it can remove the non-moving (usually background) items from a video. This is the technique used in video chats that allow background replacement, for example. (There may also be some help from facial recognition or something like that.) It's cheap and will get the job done, but it won't look perfect. (If filmed perfectly, this technique can be used in professional quality FX, but it's usually harder overall than just using bluescreen, so it's not very common.)


You can search on google for any of the topics above. If you plan to automate this and put it into a website, it will be very, very difficult. That said, it would be fun so good luck and post a link when you're done. But be prepared for a tough project.



As for just changing the background in an animation, the answer is very simple: create a foreground video with transparency (alpha channel). Then switch the background in as needed. This technique could also be used for live action (real people) assuming you pre-process all of the videos and are only allowing background-changing, not custom foregrounds.


After all of that is done, switching the background will be easy. But preparing the video may not be.

Hope that helps you get started.

[heimannm]

Our client a artist and have several shows albums. it requirement is remove all other singers thats play with stage.
I don't have any idea that how to?? I have flash converter but basic problem is video background how to edit?????

[djr33]

This is a live recording against a normal (not specially designed) background?

Read my post above. The information is there. You will need to contract with an FX artist, I think. Note that this is how companies like ILM and others make all of their money: this is very hard. Of course everyone wants an easy way, but the only way at the moment is with years of experience and lots of work.

Tell your client this is difficult and expensive. Can they film it again?