thicken lines in jpeg

[rnmerchant]

I have an image with a number of lines that are quite 'thin' - essentially only a few pixels.

I want to use a laser burner to burn it too wood - but the lines are too thin to make a good image.

Is there a way to selectively "thicken" such lines? I could print it and then use a marker to make the lines thicker, then scan the image, but that is so '80's......

Thanks.

[Kathy_9]

It's hard to say without seeing an example. I would suggest trying Effects - Edge Effects and try the different options there to see if it gives you what you are looking for.

[Jean-Luc]

I have an image with a number of lines that are quite 'thin' - essentially only a few pixels.

Difficult to give advice without seeing the problem.
Could you post an example here? Send a crop if you don't want to publish the complete image.

[LeviFiction]

You could use the brush tool to draw over the lines, it's exactly the same as drawing over them with a marker except you skip the printing and scanning steps.

For more control you can use the pen tool to draw vector lines and control their width.

You can try making selections and fill them in.

You can duplicate the layer, do what kathy_9 suggested or any effect really just play around and see if anything makes those lines bigger automatically and then erase any part of the new layer you don't want to have the effect applied to.

[rnmerchant]

I'll attach the image I'm trying to print.

I indeed can draw over the lines - but I don't have a very steady hand with a mouse, it seems.... I was wondering if it could be automated. I'll try Kathy_9's edge effect suggestion.

[rnmerchant]

I should note too that I did try converting to vector, and outlining in CorelDraw but all I got was a 'dog's breakfast'. Quite useless despite what I thought should have been an easy project there.
Richard

[Jean-Luc]

Like this?

If yes, I'll give you my steps.

[rnmerchant]

Yes - that seems much more like something that should burn/print... Thanks Richard

[Kathy_9]

Looks like the Edge Effect that works best on this image is Erode. I repeated the process 3 times to get this.

[rnmerchant]

Looks good! Thanks ...

[Jean-Luc]

My steps :

Gaussian blur: Radius 4 (may vary with image's size)
Duplicate the blurred layer
Change the blend mode of the duplicate layer to Multiply
Merge down the duplicate layer
Histogram adjustment (Ctrl+Shift+H): Luminosity Midtones: compress -50 (expand)
Drag the left cursor to the right until the Low value reaches 120, and the right cursor to High value 220

Those two sliders control the white and the black.
Last step : do Adjust/Brightness and Contrast/Brightness and Contrast tool ->Contrast: 80

[rnmerchant]

Thanks for this - finally got back to this project.

Looks good - I'm going to try using it now.

Thanks for your detaile help!

[Andy2011]

Probably a bit late for this but perhaps the following technique may be of use in future.
The (Effects/) User Defined Filter can be applied to thicken lines.

What this is doing is copying pixels all around the lines. The -1 value at the edge sharpens. Don't forget to compute the Divisor (3 in this case).
I suggest setting the image to greyscale before applying the filter.
The Before/After in the fliter control shows the impact on the rotor blade is quite subtle but effective.
The parameters can be saved as a preset for a quick fix for other jobs.