Posted by
lechristophe on
Oct 25, 2006; 6:18pm
URL: http://imagej.273.s1.nabble.com/once-again-can-i-draw-cylinders-tp3701191p3701197.html
Sorry, my response was about ROI, not drawing.
First of all, ImageJ is not really a drawing program. Similar to
Photoshop, it can be incredibly difficult to draw the simplest things.
Plus you don't have the layer feature to avoid destroying your image. If
you just want to draw on images I suggest you use vector programs like
Illustrator (or it's open source competitor, Inkscape).
If I understand correctly, you want to draw rectangles with one pixel
borders and no fill ? That should correspond to "lines with width but no
fill".
I don't know how to do that with any line, but for horizontal or
vertical, you can do that :
- Select a rectangle ROI
- Store this ROI in the ROI manager (Edit/Selection/Add to ROI Manager)
- Shrink it by the number of pixels desired : one in this case with
Edit/Selection/Enlarge with -1
- Store the shrinked ROI,
- Substract the shrinked ROI from the inital ROI. To do that, select the
shrinked ROI, do a copy to the clipboard (Edit/Copy), select the initial
ROI, clear it (SUPR or Edit/Clear), and paste the shrinked ROI
(Edit/Paste) that will re-fill the inside of the rectangle with the
initial image, leaving just the one pixel frame.
For any kind of lines (inclined rectangles, even segmented or freehand),
a workaround using the macro provided yesterday by G. Landini but
defining two expanded ROIs one pixel appart and copy/pasting the inside
one could work.
Christophe
sridevi polavaram wrote:
>> solid line. I want to see it as a cylinder (i.e) hollow line with width
> but no
>> fill....can i do that?
> like i posted, I don;t want solid lines...like how you said, i could draw
> line with width but i don;t want the fill
>
> On 10/25/06, Christophe Leterrier <
[hidden email]> wrote:
>>
>> once again : double click on the "Straight line selections" tool, set up
>> the slider to the number of pixels you want, and you're done.
>>
>> Alternatively, you can get the selection dialog with "Edit/Otpions/Line
>> width..."
>>
>> This works for straight lines, and the resulting ROI is still considered
>> as a line, not a surface, with subtle ways to process things like
>> intensities along the line, I think averaging in the direction
>> perpendicular to the line for each point - correct me if I'm wrong but I
>> seem to remember a discussion about that on the list.
>>
>> sridevi polavaram wrote:
>> > I want to draw lines with width let's say 4. But i don't want it like a
>> > solid line. I want to see it as a cylinder (i.e) line with width but no
>> > fill....can i do that?
>> > -Thanks
>> > Sri
>> >
>>
>