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Member Since 02 May 2006
Offline Last Active Jun 12 2014 11:15 AM

Topics I've Started

Google Summer of Code 2014: Help Neuroscience and Biology by improving Image Processing...

07 March 2014 - 04:10 AM

To all the students out there:


Are you interested in applying your coding skills and rendering / image processing / machine learning experience to some other field than game development? How about being a Google Summer of Code student this summer, working 3 months coding, and earning 5500 USD?


At the Heidelberg Collaboratory for Image Processing we're developing an Open Source tool called ilastik that is used by Biologists to analyze terabytes of data coming from advanced microscopes. We proposed a set of ideas to the Google Summer of Code program where students are paid to work on selected Open Source projects because we are looking for talented programmers who want to contribute to software used at the bleeding edge of neuroscience and developmental biology.


Possible project ideas related to ilastik:

Visualization projects:

  •  Use OpenGL for blending layers in Volumina
  •  Improve 2d/3d object browser in volumina
  •  Multiscale views based on pyramids in volumina


Software infrastructure projects

  • User Experience Improvements in ilastik
  • VIGRA Java bindings
  • Parallelization of the VIGRA library


Image processing projects

  • Lazy connected components in VIGRA
  • Image features for machine learning in VIGRA

Detailed descriptions available here. If you're interested, get in touch with us now - application deadline is March 21st!




NeHe iOS Lesson 01 Q&A

27 October 2011 - 05:05 AM

Hi guys!

I've just finished and published the first iOS NeHe Lesson!!


Would be great to get some feedback, no matter how destructive :) !

This is to place to ask any questions about it as well, so feel free to do so.


Floating point texture on iPhone GLES 2.0

13 August 2011 - 01:09 AM

Hi everyone,

I'm trying to use a float image as OpenGL texture in an iPhone app. The float data is computationally generated, real 32bit floats.
Now according to the supported extension OES_texture_float I should be able to use GL_FLOAT as type parameter for my texture. But I cannot find which internalformat types are allowed for glTexImage2D that would suit a float texture.



glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, size.width, size.height, 0, GL_RGB, GL_FLOAT, imageTileData);

I've tried GL_RGB and GL_RGBA for both format fields, but can't find equivalents for GL_RGB32F which would be what I intend to use. glGetError returns a GL_INVALID_VALUE.
My whole setup works with non-float textures btw, so it's really the GL_FLOAT and format combination that causes the error.

Any ideas? Thx in advance!

VBO with Element Array Buffer - weird problem

16 February 2009 - 10:19 AM

Hey all, I guess I'm just overlooking something, but my triangles just does not show up when rendering with my ElementArrayBuffer. I'd be glad if somebody can find the error and point it out to me! VBO setup:
void Scene::createVBO()
    glGenBuffers(1, &_vboVertices); //Generate a buffer for the vertices
    glBindBuffer(GL_ARRAY_BUFFER, _vboVertices); //Bind the vertex buffer
    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * _vertexCount * 3, _vertexData, GL_DYNAMIC_DRAW);

    glGenBuffers(1, &_vboElements);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _vboElements);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLuint) * _triangleCount * 3, _indices, GL_STATIC_DRAW);

Usage when drawing:
    glBindBuffer(GL_ARRAY_BUFFER, _vboVertices);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _vboElements);

    glVertexPointer(3, GL_FLOAT, 0, 0);
    //This works:
    //glDrawArrays(GL_POINTS, 0 , _vertexCount);

    //This does not:
    glDrawElements(GL_TRIANGLES, _triangleCount, GL_UNSIGNED_INT, 0);


The buffers are all of the correct data type (vertexData is float*, indices a unsigned int*) and _indices does indeed contain indices to 3 different vertices per triangle. glGetError returns NoError, culling and lighting are disabled(Rendering just the points without ElementArrayBuffer works!). I can't think of anything else to check. Any ideas?

GL 3.0 basecde Beta for Windws and Linux(GLX)

27 October 2008 - 09:07 AM

Hey everybody, after a long time with no news (we've been pretty busy with other projects) here's a new basecode! As OpenGL 3.0 drivers for NVidia cards are out for Windows and Linux now I've set something up for you: a sample for setting up an OpenGL 3.0 context. This code is not completely finished yet and lacks loads of comments (especially in the GLX window part), but its there for you to test and criticize! You need to have the appropriate drivers installed to run the code: Windows: Forceware 177.89 or later, GL 3.0 enabled with nvemulate as explained on the NVidia page Linux: Forceware 177.61 from the same nvidia page. Download it here and tell me what you think. There's a project file for: Linux - Code::Blocks: Lesson01GLX.cbp, you need libXxf86vm-dev installed Windows - Visual C++ Express: Lessn01Win.vcproj Please tell me about everything you don't like, don't understand, do like or whatever [smile]. Cheers Carsten (aka Caste) @ NeHe Team [Edited by - Caste on October 27, 2008 5:09:35 PM]