Graphics

2-Nov-09 8:30

Hi everybody,

I'm here in the graphics corner coz it's much more of a general graphics question which starts like "Is it possible...?" or "Does the approach make sense"?

We're restoring an ancient movie, which has severe damage on the blue layer over a huge number of frames. One of the ideas for restoration is to safe a non-damaged frame/image from every scene as reference, erase the blue layer from all the frames and compute it newly for the damaged frames, based on the reference image from the same scene. Seems to make sense, but how to implement such a task in a VB program?

How would I extract the blue histogram from the reference image and implant it into the other frames in VB?
Any advice and/or better idea is very welcome!

Thank you in advance
Michael

C^hris L^osinger3-Nov-09 6:44

3-Nov-09 6:44

Michael Schäuble wrote:
Seems to make sense, but how to implement such a task in a VB program?

it's hard to answer that without knowing how you are storing your image data. the format you use to hold the image data will determine what you have to do to get at the blue channel.

Sonhospa3-Nov-09 8:08

3-Nov-09 8:08

Hi Chris, thanks for your time.

The files are in 10-bit DPX format (linear RGB), which is basically an uncompressed bitmap format and unsupported from GDI+. By now I read it into a RGB Array and throw 2 bits in order to have it displayed, so I have a System.Drawing.Image object I can access and e.g. put it into a picture box. Is that the additional information you needed or did I misunderstand you?

C^hris L^osinger3-Nov-09 10:51

3-Nov-09 10:51

if you have the RGB array, you should be able to simply copy the B data out of it, right?

maybe i'm misunderstanding now.. Smile | :)

Sonhospa3-Nov-09 12:10

3-Nov-09 12:10

Maybe I didn't make it clear enough... I don't want to extract the blue channel. What I want is to

1. detect some kind of 'blue level' in a reference picture (only one, non-damaged frame)
2. transfer it to a complete series of other frames/images (the whole scene), from which the (damaged) blue channel had been erased before.

Like when you re-adjust the color levels in a histogram in order to get natural colors - but automatically, using a reference instead of user interaction. Is that clearer?

Tim Craig3-Nov-09 14:44

Tim Craig

3-Nov-09 14:44

Even if you have the blue data from an undamaged frame, how are you going to decide which pixels in the damaged frames to apply it to? The pixels will move around as the scene progresses. (I'm assuming the blue data in the damaged frames is total garbage) If you could partition each frame into regions and match the regions between frames, you might apply the blue by region and maybe adjust it based on correlation with the red and green channels with some hand adjustment if needed and that "if" is more like "probably".

Have you researched how they apply the colors to old black and white movies? I know in the early days they did that by identifying regions and hand selecting colors which were then automatically propagated forward with hand touchups. Hopefully, that has progressed since the last time I read anything about it.

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

C^hris L^osinger15-Nov-09 6:33

15-Nov-09 6:33

what if you simply copy the blue channel from an undamaged frame to the next N frames? it won't match perfectly, but it might be better than nothing.

otherwise, yes, you could generate a histogram from the blue channel of an undamaged frame, then try to force the blue channel in subsequent frames into a similar distribution (find black % and white % from the good frame and then stretch the bad frames to match those %s). that would be pretty simple.

Sonhospa19-Nov-09 21:16

19-Nov-09 21:16

Chris,

this sounds exactly what I imagined ...! And 'that would be pretty simple' sounds extremely teasing Laugh | :laugh:

.

The blue channel isn't completely damaged, it's more or less stained in the blue resulting from fungus that affected irregular regions on the upper/outside layer of some frames. Playing the movie, it looks a bit like ghosts swirling around.

Since there seems to be a way on the basic ideas path, I'll try to find some code samples when I have some extra time again. Or do you even have a link or snippet available that leads in the right direction?

Thanks for now,
and have a nice day
Mick

C^hris L^osinger20-Nov-09 4:26

20-Nov-09 4:26

here's a quick thread on histogram stretching: http://stackoverflow.com/questions/1295057/i-need-to-do-a-histogram-stretch[^]

How to draw cross hair cursor in opengl while rotating camera ??

maheshbhoir.home30-Oct-09 20:25

maheshbhoir.home

30-Oct-09 20:25

Hi,

I am displaying 3D models using opengl and VC++.
I have implemented code to rotate, move, zoom the model by moving camera (using gluLookAt() )
Now I want to add one cross hair cursor in front of camera view port(at center of screen), but when I tried to rotate or zoom the model the cursor also rotates or zoom along with model.
How I can make cursor lie at same position while rotating model.

Please help me Cry | :((

Re: How to draw cross hair cursor in opengl while rotating camera ??

ARon_2-Nov-09 9:31

ARon_

2-Nov-09 9:31

After you are done rendering the rest of the scene, reset your view matrix and projection matrix to width and height of your screen and with and ortho projection. Then Draw your cross hair in the center. It does not have to exist in world space. Basically, it is a HUB display on the near plan of your view.

ARon

Re: How to draw cross hair cursor in opengl while rotating camera ??

maheshbhoir.home2-Nov-09 18:17

maheshbhoir.home

2-Nov-09 18:17

But I want to do only rotation on cursor (it is same as three unit axes rotates about one fixed point) which was done on entire 3d model but to avoid pan and zoom operations. How to do this ???

Re: How to draw cross hair cursor in opengl while rotating camera ??

ARon_3-Nov-09 4:36

ARon_

3-Nov-09 4:36

I not sure what you are trying to do but this is how I draw an object(s) in space. Forgive me it I c#.

static public void RenderScence()
        {
            Object LockThis = new Object();
            lock (LockThis)
            {
                Gl.glClear(Gl.GL_COLOR_BUFFER_BIT | Gl.GL_DEPTH_BUFFER_BIT);

                #region Draw Scene From Camera View
                #region Set the Current Camera Matrix
                //  Get the Current Cameras View Transform and Load it in to OpenGl Projection Matrix
                Matrix_44 HTotal = CurrentCamera.HTotal;
                Gl.glMatrixMode(Gl.GL_PROJECTION);
                Gl.glLoadIdentity();
                //  Then I clear the ModelView Matrix as it is overriden by each Drawable Object
                Gl.glLoadMatrixf(HTotal.GetListValues());
                Gl.glMatrixMode(Gl.GL_MODELVIEW);
                Gl.glLoadIdentity();

                #endregion
                //  Draw each visible object
                foreach (ISpatialNode obj in WorldObjectList)
                    if (obj.IsVisible) obj.RenderOpenGL();
                #endregion

                Gl.glFinish();
            }
        }

Base on your description I would create a crosshair class and maintain it orientation and position in the world. When it is time to render the crosshair I would just loaded its Position and Rotation in to the ModelView matrix and then draw it as if it were in free space.

References.
My article on transforms easily adapted to c++.
Space and Matrix Transformations - Building a 3D Engine[^]

Others probably better
Interactive Techniques in Three-dimensional Scenes (Part 1): Moving 3D Objects with the Mouse using OpenGL 2.1[^]
A New Perspective on Viewing[^]
Arcball Module in C# - Tao.OpenGL[^]

ARon

Re: How to draw cross hair cursor in opengl while rotating camera ??

maheshbhoir.home3-Nov-09 17:50

maheshbhoir.home

3-Nov-09 17:50

Thanks for ur reply.
I have tried to reset the modelview matrix and projection matrix and I am successful to display axes 90 percent, the remaining problem is that while rotating the 3d model flickers (at start zoom - in and at end at normal size and position).

I have tried this code after finishing of rest 3d model drawing :

glMatrixMode(GL_PROJECTION);
glGetDoublev (GL_PROJECTION_MATRIX, projMatrix);
glLoadIdentity(); // reset projection matrix

GLdouble gldAspectRatio = (GLdouble) ViewportSize.right/(GLdouble) ViewportSize.bottom;

glOrtho ( pViewVolumeAxe[0], pViewVolumeAxe[1], 
	  pViewVolumeAxe[2]/gldAspectRatio,
	  pViewVolumeAxe[3]/gldAspectRatio, 
	  pViewVolumeAxe[4], pViewVolumeAxe[5] );

glMultMatrixd(projMatrix);

glMatrixMode(GL_MODELVIEW);
glGetDoublev (GL_MODELVIEW_MATRIX ,modelMatrix);
glLoadIdentity(); // reset model view matrix

// do reverse translation as to keep axes at same position
glTranslated(-modelMatrix[12], -modelMatrix[13], -modelMatrix[13]);

glMultMatrixd(modelMatrix);

// translate whole setup to model center currently I am     // displaying at origin(0,0,0) 
glPushMatrix();
glTranslatef(fXTrans, fYTrans, fZTrans);    

// then all axes draw stuff

collapsible regions !

amir-haghighi30-Oct-09 6:11

amir-haghighi

30-Oct-09 6:11

Hi.
I can not good speack english . I want to collapsible regions (selected text) in the richtextbox control .

please see this image ::

http://www.sapphiresteel.com/IMG/gif/collapsible_region.gif

My language is C# .

Re: collapsible regions !

enhzflep3-Nov-09 6:25

enhzflep

3-Nov-09 6:25

Hi.

If I understand you correctly. the term you're searching for is 'Code Folding[^]'

please

Archy_Yu25-Oct-09 4:44

Archy_Yu

25-Oct-09 4:44

The program in OpenGL with Texture just didnot work in my cimputer,which work well in others' computer.
where is the crux,any help is appreciated.
The code is in the former message.

RichardM128-Oct-09 8:44

RichardM1

28-Oct-09 8:44

I can't give a good answer for this, but I can comiserate:
If I use a rectangle to exclude an area from a Graphics drawing area in C#, on some machines it also excludes the pixel before and the pixel after the intended exclude area, but only for the horizontal axis.
Same video chip set on all machines, various drivers.
I just worked around it, but what a pain.

Silver member by constant and unflinching longevity.

Tim Craig29-Oct-09 15:35

Tim Craig

29-Oct-09 15:35

From your code, it looked like the program gets the texture from a separate file. Did you copy the texture file to your computer along with the .exe?

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

Archy_Yu29-Oct-09 16:50

Archy_Yu

29-Oct-09 16:50

First! Thanks for you help!
then, how could i copy the texture file to my compter along with the .exe!
I could not understand you say.