Ok. Image processing subject, ingeneering university, UBA, final work. The guy that gives the practical classes, who's in charge of this work, is quite, errr
So
it's more about searching for a paper, reproducing it, and giving him whatever so that he has an excuse to make me pass
Over on the TeX stackexchange, we have been discussing how to detect "rivers" in paragraphs in this question.
In this context, rivers are bands of white space that result from accidental alignment of interword spaces in the text. Since this can be quite distracting to a reader bad rivers are co...
As you already have the barcode position, you could generate a mask automagically and perform a Navier-Stokes Image Restoration.
Example in Mathematica:
@Rojo You shouldn't allow a salad to control your lifestyle. It's just dirty grass. Go for beer: noble cereals. The whole story of mankind is told in each glass of beer
I have tried to use NDSolve for solving a system of second-order ordinary differential equations by giving some boundary conditions.
I set the parameters of NDSolve as follows:
sol = NDSolve[{eq1,eq2,q1[0] == 0, q2[0] == Sqrt[2], q1'[0] == 0, q2'[0] == -2},
{q1, q2}, {t, 0, 0.5}, MaxSteps -&g...
@Rojo JPEG has a default quantization table that isn't really mandatory. You could make an interactive mma app playing with the quantization components and show how it works out on various types of images. It would also be interesting to optimize the q table automatically based on the image content.
I mean, if we place pictures on SE, there is a link in the text to the image. If you upload a better one and replace the link with a new one, I can imagine they do some kind of garbage collection. Throw away all images that are not referred to in either a Q or an A
anybody knows why expr = Sin[10^23];{N[expr, 15], N[expr], N[expr, 17]} gives {0.701140639861078, -0.3240539376430033, 0.70114063986107847} ? I mean why is MachinePrecision so special ($MaxExtraPrecision increase does not seem to change anything here)
@RolfMertig precision tracking is switched off at MachinePrecision, so numerical errors accumulate without being noticed. For any other precision, including $MachinePrecision, it's on, so when the precision starts dropping, more is added.
@RolfMertig Also, different algorithms are used for machine precision and arbitrary precision.
If memory serves, a minimax approximation is used for machine precision, and other methods are used for arbitrary precision. That might explain the difference.
So, I was thinking about this answer that I wrote yesterday, which also answers this question. Does anyone know how/why NonlinearModelFit is able to work with complex-valued functions in some cases but not others?
In other words, is there a well-known approach for complex nonlinear least squares that's better than transforming an n-dimensional complex model to an (n +1)-dimensional real one and fitting that? (I guess this can't be what NonlinearModelFit is doing, otherwise it wouldn't be running into difficulties. Also, the choice of transformation needed to do this is somewhat arbitrary.)
Hello; I am wondering if its appropriate to ask a question about identifying critical points of a 2D field/image (maxima, minima saddle points). I.e. the generalisation of mathematica.stackexchange.com/questions/5575/…
Stan Wagon's Mathematica in Action (second edition; I haven't read the third edition and I'm hoping to eventually see it), demonstrates a nifty function called FindAllCrossings2D[]. What the function basically does is to augment FindRoot[] by using ContourPlot[] to find crossings that FindRoot[] ...
As you already have the barcode position, you could generate a mask automagically and perform a Navier-Stokes Image Restoration.
Example in Mathematica:
I have tried to use NDSolve for solving a system of second-order ordinary differential equations by giving some boundary conditions.
I set the parameters of NDSolve as follows:
sol = NDSolve[{eq1,eq2,q1[0] == 0, q2[0] == Sqrt[2], q1'[0] == 0, q2'[0] == -2},
{q1, q2}, {t, 0, 0.5}, MaxSteps -&g...
