Wednesday, 24 September 2014

Trimming Images in Inkscape

How can you prepare your own images to print them, then cut them out with a digital cutter? I'm sure there are many ways, but I use Inkscape. Now, we have a small problem here. I don't want to violate anyone's copyright, so I am going to have to subject you to a naff little drawing I threw together for this tutorial.

Click on any image to open a larger preview.

I start by loading my image into Inkscape with a spot of drag and drop.

1. Zoom in. Select the zoom tool and draw a box around the area that you want to zoom in on.

2. Select the pen tool (I have no idea if that's its real name)

3. Click somewhere on the edge of the bit you want to cut out and just keep clicking in small steps right round that area (ie the part you want to cut out) until you get back where you started. You can do this more quickly using curves if you are familiar with vectors, but this is the best way (if a bit tedious) to begin.

I have zoomed in massively so you can see what I mean but in reality I would work at a lower resolution in fairly gung-ho fashion.

While you are actually drawing the line it will be hard to see. It should look pretty much like this (were you able to see it!!!)

4. You need to be a little bit on your guard here. If the line turns black like this, and I bet it will while you are learning, Inkscape has decided you were finished with that line. Don't panic! Just Click with the pen tool on that last point and you can pick up where you left off.

If the line is black with no squares showing at the end, press the N key to "edit path by nodes". Then when you select the line all the nodes will show, choose the pen tool again, click on that last point and off you go.

5. Finally, click on the very first point and your path should join up. To show you just how many times I clicked, and what it looks like using the node tool, we have the following image:

6. Now if you want to (and know how) you could smooth up some of those paths by pressing N and using the edit node tool to select points (= nodes) and delete them or drag them to a neater place. But I'm going to settle for what I have.

7. Press S for the select tool and select the shape you drew, then hold down shift and select the image, so that you have them both selected.

Now (still with them both selected) hold down Control and press D. This duplicates both of them right on top of the originals.

Next open the Object menu, choose Clip> Set and you'll see you have removed the background. Drag the new clip to one side.

8. You must save your file now, if you didn't already, as Inkscape needs to use that location for its export feature. So, first File> Save As and choose a name and location.

Next, File> Export Bitmap and you should see this box. To be honest I've never delved beneath the motor housing here. I just click Export. You won't have the same details as me because my images are low resolution for the sake of the tutorial and would not print well. I also just go with the name Inkscape chose.

So I've got the face and I also quickly did the flowers because now I'm shaping up for a bit of 3D découpage.

9. By now you may be on a roll as I was, so there is only one thing for it. Go round all the other bits of the image and make sure you overlap into the areas you already have clips for. I have put a thicker line round that part so you can see where I'm going here.

10. Now you will be glad you duplicated those bits earlier. Select them along with the shape you just made and, holding down Shift and Control, press the + (plus key). Be careful not to select the image.

Voilà! They will join together and you have the larger shape ready to make a clip. You know the small bits will fit exactly because you used the same shapes.

Select the larger shape along with the image,  open the Object menu and choose Clip> Set.

You would think that because the background is white it would be easier to just leave it (I thought so too) but it’s full of messy bits that would spoil the trace, so I prefer to get rid of it myself.

11. Now, just for découpage, press S for the select tool and arrange your pieces so they won’t take up too much paper. Then group them and Shift Control E (or File> Export Bitmap).
That is the file you will want to load to your cutting machine. The background is transparent. But I think that’s another tutorial. One for someone else.

Now, obviously, you are not all going to want to create 3D découpage of girls who look so guilty that they might have just broken your window... but I hope you can see the potential of this technique!

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