Post by thread:[TECH] Whiteboard image extraction

Philip Pemberton wrote: > Speaking of whiteboard image extraction.. I've been (slowly) hacking > away at a program that takes a JPEG file containing a photo of a > whiteboard, removes the brightness variations caused by light shining > on it, makes the background pure white, and enhances the contrast so > you can see the text properly. I've captured whiteboard images a number of times with great success using two pictures. Set the camera on a tripod, take the first picture, erase the board, then take the second picture with the same lighting and the camera in the same position. A little image subtraction and scaling with existing image manipulation programs and you get a very nice copy of the whiteboard scribbles. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.

"Olin Lathrop" wrote: > Philip Pemberton wrote: >> Speaking of whiteboard image extraction.. I've been (slowly) hacking >> away at a program that takes a JPEG file containing a photo of a >> whiteboard, removes the brightness variations caused by light shining >> on it, makes the background pure white, and enhances the contrast so >> you can see the text properly. > > I've captured whiteboard images a number of times with great success using > two pictures. Set the camera on a tripod, take the first picture, erase > the > board, then take the second picture with the same lighting and the camera > in > the same position. A little image subtraction and scaling with existing > image manipulation programs and you get a very nice copy of the whiteboard > scribbles. We don't have room for a tripod in the conference room, and it is just more convenient to grab the camera, and snap a picture. The whole process (from taking a picture to getting the printout) takes an average of three minutes. Most of that time is spent walking. :) It's one of those "if it works, why fix it?" situations -- the whiteboard is well-lit, when you crank up brightness/contrast in MS Photo Editor, it produces crisp text on a black background. I'll try to post an example one of these days. Vitaliy

--- On Sun, 1/2/09, Vitaliy <spam_OUTspamTakeThisOuTmaksimov.org> wrote: "Olin Lathrop" wrote: > Philip Pemberton wrote: >> Speaking of whiteboard image extraction.. I've been (slowly) hacking >> away at a program that takes a JPEG file containing a photo of a >> whiteboard, removes the brightness variations caused by light shining >> on it, makes the background pure white, and enhances the contrast so >> you can see the text properly. If you need to make a line (vector) drawing from a bitmap/jpeg picture of the whiteboard, maybe try the auto-trace/live-trace(?) function in Illustrator? My 20c worth - Debbie :) Make Yahoo!7 your homepage and win a trip to the Quiksilver Pro. Find out more

Vitaliy wrote: {Quote hidden}> "Olin Lathrop" wrote: >> Philip Pemberton wrote: >>> Speaking of whiteboard image extraction.. I've been (slowly) hacking >>> away at a program that takes a JPEG file containing a photo of a >>> whiteboard, removes the brightness variations caused by light shining >>> on it, makes the background pure white, and enhances the contrast so >>> you can see the text properly. >> I've captured whiteboard images a number of times with great success using >> two pictures. Set the camera on a tripod, take the first picture, erase >> the >> board, then take the second picture with the same lighting and the camera >> in >> the same position. A little image subtraction and scaling with existing >> image manipulation programs and you get a very nice copy of the whiteboard >> scribbles. > > We don't have room for a tripod in the conference room, and it is just more > convenient to grab the camera, and snap a picture. The whole process (from > taking a picture to getting the printout) takes an average of three minutes. > Most of that time is spent walking. :) > > It's one of those "if it works, why fix it?" situations -- the whiteboard is > well-lit, when you crank up brightness/contrast in MS Photo Editor, it > produces crisp text on a black background. I'll try to post an example one > of these days. One thing I've found useful is to use the video camera instead of the still camera. It seems to get more information and I can't keep a camera very still. -- Linux Home Automation Neil Cherry .....ncherryKILLspam@spam@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies

Vitaliy wrote: > It's one of those "if it works, why fix it?" situations -- the > whiteboard is well-lit, when you crank up brightness/contrast in MS > Photo Editor, it produces crisp text on a black background. I'll try > to post an example one of these days. I never said you should change your way, only described a way that has produced very nice results for me in the past. I put one example at http://www.embedinc.com/temp/board.tif. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.

On Sat, 31 Jan 2009, Neil Cherry wrote: > One thing I've found useful is to use the video camera instead of the still > camera. It seems to get more information and I can't keep a camera very > still. The biggest drawback with digital image sensors is they are not very sensitive to light, so they require long esposure times which leads to blurry images. The reason a video camera usually gives better images is that the sensors tend to be larger, allowing more light to hit each cell, and the resolution is much smaller. Think 1 megapxel vs 10 megapixels. Much less noise. One thing to try is set your camera to the highest ISO setting, and reduce the resolution down. You loose resolution to gain sharpness. -- Ian Smith http://www.ian.org

"Olin Lathrop" wrote: > I never said you should change your way, only described a way that has > produced very nice results for me in the past. I put one example at > http://www.embedinc.com/temp/board.tif. It looks great. What are the numbers next to the to-do items? Ratings in terms of difficulty? What do the numbers next to the names mean? Amount of work accomplished? Vitaliy

Alan B. Pearce wrote: > >What are the numbers next to the to-do items? >>Ratings in terms of difficulty? >> >>What do the numbers next to the names mean? >>Amount of work accomplished? > > I took them to be priorities and assignments of jobs to people. I don't think they can be assignments of jobs to people, the numbers repeat. Priorities are usually not expressed as fractional numbers. In Agile/SCRUM/XP they sometimes assign "points" to tasks (the point system is relative, and unitless). So for example, if you have three tasks, and Task A is twice as difficult as Task B, which in turn is twice as difficult as Task C, the points would be assigned thus: Task A: 4 Task B: 2 Task C: 1 If you have Task D that is considered to be three times as hard as Task B, it would get assigned 6 points. What this allows one to chart the team's progress (how many "points" were done in a particular week). Last I heard, this practice has been abandoned by some, in favor of the old way of assigning the number of hours to each task. Vitaliy

Vitaliy wrote: > What are the numbers next to the to-do items? Ratings in terms of > difficulty? Cans of Jolt required for completion. > What do the numbers next to the names mean? Amount of work > accomplished? Number of days docked for going home on weekends, attempts to remove leg shackles, that sort of stuff. Seriously, this is just a example of whiteboard capture. The project is long over, but I don't want to give information about it. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.

On Jan 31, 2009, at 2:46 PM, Olin Lathrop wrote: >> What are the numbers next to the to-do items? Ratings in terms of >> difficulty? > > Cans of Jolt required for completion. That's funny. I've considered that I might be able to charge for consulting by counting the number of cans of Dr Pepper consumed; that providing some sort of balancing influence between time spent and intensity involved that might otherwise be lacking. I suspect customers wouldn't go for it though... BillW

William "Chops" Westfield wrote: >>> What are the numbers next to the to-do items? Ratings in terms of >>> difficulty? >> >> Cans of Jolt required for completion. > > That's funny. I've considered that I might be able to charge for > consulting by counting the number of cans of Dr Pepper consumed; that > providing some sort of balancing influence between time spent and > intensity involved that might otherwise be lacking. I suspect > customers wouldn't go for it though... :-) Do you think it would be possible to create a scale of intensity, based on the type of drink consumed? I don't drink Jolt, and very rarely dring Dr. Pepper, but I find that when things start to get difficult I switch from tea to Coke, and eventually to extra-sweet strong coffee. Vitaliy