Web review

I’m back from lessons of Dr. Antonio Camurri, professor at the university I attend. He teaches “Image Processing” to us, and he presented his software, a free real-time audio/video processor, that can elaborate data from several sources (AVI or cameras, also from normal Webcams and/or PC microphones).

EyesWeb (this is the name of the software) works like Microsoft GraphEdit, the famous tool to convert multimedia files using directshow filters, throught a visual blocks interface.

The software is very interesting: it allows to create realtime effects also on live images from a simple PC webcam, adding and connecting the various blocks that are included in the base installation. Developers can also write new blocks (using C++ language).

The main advantage of this piece of software is, I think, its great speed, that doesn’t require a NASA PC to create good effects.

An example:

let’s drag the “FrameGrabber” block from the left column (Imaging > Input) to the “stage” on the right. Then double click it and choose your webcam from “Device” field.

Now drag also the “Display” block from the “Output” folder and place it near FrameGrabber; click on the little rectangle (the pin) on the perimeter of FrameGrabber block and then on that one of Display block, to connect them, like the figure.

Now we’ve a simple… viewer of our webcam To check if it works, press ALT+K on the keyboard. You should see live images from your webcam (Eyesweb will ask you to save your project, the ”patch”. Feel free to save it or just to click on cancel, anyway it’s better to save it, so it will stop to ask you again). When you’re ok, press ALT-H to stop it.

Let’s do something interesting: click on the link between FrameGrabber and Display and press DEL on the keyboard, to delete it.
Now drag 3 copies of “ExtractChannel” (Imaging > Operations, in the block browser) and connect FrameGrabber to them, like I did on the left.
Double-click on each of them and choose rispectively Channel 1, 2, 3 for the 1st, 2nd and 3rd block. So we are separating Red, Green and Blue channels of our source.

We want now to set a different delay for each of the 3 channels: drag 3 copies of the “Queue” block (from the “Generic” folder), and connect each of them with each of the ExtractChannel blocks.

Open properties of each Queue block and set a different delay (called “Lenght“) for each of them. My choice was to set them rispectively to 5, 10 and 15.

Finally, we have to recompose the image and to reactivate the display: drag one “ComposeChannels” block (Imaging > Operations), connect the 3 pins of Queue blocks to it, and it to the display block:

Our Graph is complete. Press on ALT+K to see it in action!

Please take note that I didn’t understand how to make last EyesWeb version (4.0.2.0) work. This little introduction is based on version 3.3.0.

http://www.eyesweb.org

This content was posted Wednesday 10 May 2006 on 10:58 pm in category Apps. You can follow the comments in this article with its dedicated feed in RSS 2.0. Here you can leave an answer. Pinging is not enabled.