I want to periodically capture images through a webcam, modify the captured image and display it on a monitor. I can of course use OpenCV for that purpose, but OpenCV is big and complex. I want to have some code which can be easily ported from one system to another and therefore not depend on a big library. So my question is, is there any sample code for what I'm trying to do without using OpenCV or any other library?
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I am coding a raytracer engine in C using X11 on a Linux. I would like to add a screenshot feature but I can't use any other lib than the standard X11.
Is there a "simple" way to do that, or do I have to create a bmp file myself from the pixels I have?
You will manually have to get color values of all the pixels and then convert it to a format of your choice.
AFAIK, there is no "simple" way to do it.
You can check with this question here: How do take a screenshot correctly with xlib?
I want to read and display a png image using c programming. Please suggest some ways. Is it possible to use libPng library for displaying image ?
libPng will only decode the image into an RGBA-array for you. To then display the image you could use OpenGL or an OS-dependendent graphics-library.
EDIT: Since you say you are using windows:
On Windows you have many library choices: I suggest you start with SDL, you can start by showing your image like this: http://www.sdltutorials.com/Data/Posts/105/ss1.jpg and then continue building your application from there. There are many tutorials on SDL (see here: http://www.sdltutorials.com/tutorials). The JPG was from this one: http://www.sdltutorials.com/sdl-coordinates-and-blitting
hi every one i want ask that i have made a program and i have store a data in csv file. now i want a gui which includes buttons which upon pressing opens a a file and plot a graph.is there a way through which i can add gui in my program using gcc.and also i want to ask how can i make a moving graph just like ECG.
thank alot.
Have you looked into using a toolkit like GTK+, if not i would suggest you check it out. GTK+ is written natively in C so i think it should work for you.
Rephrasing your quesiton:
You have a C program that stores data in a csv file. You wish to display this information as a graph but don't know how to build a GUI or graphical display. Further, you want animation (it would be good if you linked to what "ECG" is) probably to display temporal aspects.
If I have this right, I suggest you learn the GTK and Cairo libraries and use those to build your GUI. Build GUI's is tedious and unrewarding work (to me), particularly in C. I'd think hard about if you really want to bother making a GUI instead of doing something simple like calling out to gnuplot to build the graph as a file that the user can open, though this won't get you any animation.
I suggest you switch your project to C++ and use Qt for your GUI.
If gcc is not a requirement, then check out SciPy or Octave.
I have task to create program for manipulation with 3d content on the web. When I said 3d content i mean
on 3d map (witch i have and it is something like *.sdm) which i should load into browser and work some basic operation with it (rotate screen, change camera etc...).
Because i am totaly n00b i want to ask a couple of questions:
1. How to load maps into browser. Just for notice that my map have sdm extension. Is this possible?
2. What i should use for represent 3d content. I am thinking of GLGE framework for webGL, if it is possible of course
What should be the most painless and the most effective way to do this? Maybe i was totally wrong when choose webGL?
Programs that use WebGL aren't mature enough to do what you want. Within the next few years, when GIS applications start popping up it may be possible, but not now.
Also, keep in mind that WebGL is what gives you access to a low-level graphics library. It does not directly have anything to do with GIS data.
You may want to take a look at OpenLayers (2d, javascript based) or WorldWind-Java (3d, jogl/java based). Both of these programs can display map information in a browser.
http://openlayers.org/
http://worldwind.arc.nasa.gov/java/
I would like to port an ActiveX of mine (to Silverlight) that have the following features:
Embedding a logo image in any video file.
Embedding subtitles in any video file.
Cropping any video file (for example: cropping 10 seconds of a 1 min. video).
Save the video file result (by the current encoders of the client).
The current ActiveX uses DirectShow - unfortunately, it can't be used in Silverlight. How I can abandon the old ActiveX technology for the new Silverlight technology?
The simple answer is: you can't.
Silverlight is targeted at two main types of apps:-
Content presentation, be that Video, Audio and Images, all with a view of creating interesting and engaging ways to interact with this sort of content.
More recently Line of Business apps, that is data entry and data presentation. Again with a view to making this at least a little bit more visually stimulating than prior technologies made these sorts of apps.
Video editing doesn't really fall into either of these camps and is not catered for.
I'm not sure its yet true to say the ActiveX is old, after all what technology is used to host the Silverlight Plugin in Internet Explorer? ActiveX.
I don't know if that's going to be easily doable. The various codecs natively available to Silverlight are all wrapped by the Silverlight MediaElement control, and so far as I can figure out, they're not directly exposed through an API, e.g., you can't get at the raw decoded RGBA bitstream. (If I'm wrong on this, I'd love to know, but I've poked around, and I can't figure out how to do it.) The Mono source tree has a decode-only implementation of the Dirac codec, but nothing that would easily let you decode, e.g., WMV or AVI files, so far as I'm aware.
And even if you could somehow grab the raw, decoded RGBA (or YCbCr) bitstream, so as to be able to insert whatever data you want into those frames, you'd still have to re-encode the video stream as well, and Silverlight doesn't provide any native support for that. You'd have to write your own encoders (not at all trivial), port them from the ffmpeg library (also not trivial), or wait for someone else to do it.
In short, my suspicion is that you're going to need to stick with your ActiveX solution for now -- though with some clever JavaScript coding, it might be possible to wrap that in a nice Silverlight UI.