Well, that was exactly what I tought... if the threshold is zero, only the selected colour will be selected. But what about a RGB with R=50, G=110 and B=220, and a threshold of 10? The colour range will be something like R=40-60, G=100-120 and B=210-230 ? I'm trying to implement an algorithm that does almost the same of the select-by-colour. I'm processing images taken from a microscope (I'm not sure about how do you spell this!) where are two kinds of structures, one painted of yellow and the other of red. I need to make a code for measuring the percentage of yellow, red and the space unpainted in the picture... I've already tried the steps I told you above, without success...
Do you (or anybody!) have some idea? Thanks a lot! []'s Bruno. On 11/6/05, michael chang <[EMAIL PROTECTED]> wrote: > On 11/2/05, Bruno Silva de Oliveira <[EMAIL PROTECTED]> wrote: > > Hi everyone! > > > > I'm new in the list, but I think a can ask some things... > > > > Does anybody knows how the select by color, or more precisely, the > > threshold works. How does the GIMP makes the selection using the > > threshold interval and how does this threshlold works in the tree > > channels (R,G and B)? > > I'm not sure I _fully_ understand it, but I believe I get the gist of > the function. When you select-by-colour, the colour under the pixel > is selected, and all the pixels of the same colour are selected. If > the threshold is zero (or something like that), then only the pixels > with the exact same RGB values are selected, and as you increase the > threshold, it will get further away from that colour. > > For example, if you had a gradient that went from black to green, and > you clicked on the greenest part of the gradient with select by > colour, then notice how the amount you select increases as you > increase the threshold. > > I don't know about it from a mathimatical perspective. > > If you use windows, have you considered looking at the gimpwin-users > mailing list? > > -- > ~Mike > - Just my two cents > - No man is an island, and no man is unable. > -- /** * Bruno Silva de Oliveira * http://bsoliveira.cjb.net/ */ _______________________________________________ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
