Carving Bas Reliefs of Photos

This forum is for general discussion about PhotoVCarve.
Post Reply
M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Carving Bas Reliefs of Photos

Post by M Rabin »

I have posted a similar posting on the CNC Shark forum but I wanted to also post it here. In short I am new to CNC but bought the photVcarve because I thought it could convert photos to bas reliefs. It is a great engraving program but I wanted to carve deeper wood projects. It took me two months of trolling the internet and almost giving up before I discovered that people were using gray scaling and height mapping interchangeably. They are very different. Simple gray scaling wont help in carving but height mapping using gray scaling does. I am using a program called GIMP (I didn't want to spend the money on photoshop and GIMP is free.) I have no experience with CAM or photoshop or CNC, but I knew I wanted to carve pictures. Now I can! I would be happy to post details but in brief I paint over the picture using low opacities of white and black to bring out the features. White is shallow and black is deep. I use layer after layer until the picture is right then I export it and examine the results in photVcarve over and over until it is right. Acorns and babies are relatively easy but dogs are very difficult. I chose the hardest dog I could find- mine, with black and white. Note a black nose will be a deep hole. Using GIMP I alter the colors slowly until they are the right shades of gray and then I get the final picture. If people are doing this I would love to hear about it and see if there is an easier way but like I said after 2 months of hunting I haven't found anyone converting pictures relatively easily to bas reliefs. I do lose a lot of detail doing it my way. It takes me about 30 minutes to convert a picture. I have done 8 and would be happy to post others.
Attachments
Original Phot
Original Phot
Converted picture- note the shading
Converted picture- note the shading
Final preview.
Final preview.

User avatar
Adrian
Vectric Archimage
Posts: 14544
Joined: Thu Nov 23, 2006 2:19 pm
Model of CNC Machine: ShopBot PRS Alpha 96x48
Location: Surrey, UK

Re: Carving Bas Reliefs of Photos

Post by Adrian »

With PhotoVCarve you can invert how it see the shades so it will see black as a raised rather than sunken area. That's how people are using greyscale images to do the relief cutting.

There's a PDF document here - http://forum.vectric.com/viewtopic.php?p=83746#p83746 - that explains the process.

M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Re: Carving Bas Reliefs of Photos

Post by M Rabin »

That is a great document but it shows how to carve a relatively simple object-- an acorn. I studied that document and learned about line setting but it didn't teach how to convert a detailed photograph into a gray scale picture. To do Bas Relief from a picture you must convert that picture to gray scale height mapping- it is not simply converting to gayscale. If I simply converted the picture of the dog to grayscale and then tried inverting the picture it wouldn't work-- I tried. Maybe there is a program where you can selectively convert black areas in a picture to white and white areas to shades of gray but I haven't found it.

Bob Reda
Vectric Wizard
Posts: 858
Joined: Wed Aug 16, 2006 7:34 pm
Model of CNC Machine: shopbot 48x48 upgraded prt
Location: Monessen, Pa
Contact:

Re: Carving Bas Reliefs of Photos

Post by Bob Reda »

I would be interested in learning how you did that. My main objective with PVC is to be able to do photos. I do a lot of urns and such and folks want a picture of their pet on the urn. I have been unable to get consistent results with PVC, maybe because of the size of the picture I am doing or my machine. I would be interested in learning how to do that.

Bob

M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Re: Carving Bas Reliefs of Photos

Post by M Rabin »

I posted this on CNC Shark Forum-- I will try to describe what I do but you need to be familiar with programs like GIMP or Photoshop. I import a photo that doesn't have a lot of shading or burn out by the flash-- the better the quality and the more detail the better the end product. I then use Color tab and Hue-Saturation to change the picture to black and white. I lighten it somewhat to make it easier to change the whites and blacks. I duplicate the layer several times so I can go back. I make these extra layers invisible. I then create a new layer- all layers are transparent. I always leave the original untouched. I only use FG and BG white and black- I don't use shades of gray. If I can get rid of the excess details around the dog I use 100% opacity of the paint brush and color the picture background black, I just barely overlap the picture of the dog- the subject of my cut. When this layer is complete I create another new layer. Now I darken the fur of the dog esp around the edges and under the chin. I use about 20% opacity (Need to play and see what works). In a new layer I recolor the snout using white, again between 15 and 30% opacity. I leave the nose and eyes alone. In a new layer I alter the eyes by eliminating any glare by first darkening the yes and then in a new layer I add spots of white (The brush needs to be small- I like the brush that has a soft edge to it so it will feather). In another new layer I work the nose, small brush again and 30% opacity to bring the tip of the nose very white and less white around it. It helps to keep or add a little darkness to the edges otherwise it looks like a piggy nose. Now I really look it over carefully thinking about the white-grey scaling. I check that all the objects I want out of the picture are white shades and the deep darker. I export the image and test it in PhotoVcarve. I critically rotate it and usually have to go back and make adjustments-- this is why I use so many layers. Sometimes the eyes just aren't right or the nose is bad so I throw the layer out and start that layer over without having to start the whole project over. It usually takes four or five exports to photoVcarve before it is right and then I have my wife look-- and invariably I am sent back to fix something she doesn't like. When the photo is right I go back to GIMP and save the file in GIMPs .xcf format. Now I do in image- merge visible layers. I then go to filters- blur- Gaussian I use a 5-15 blur on the picture to make it smoother- it needs to be slightly blurry to get rid of sharp edges in the cut. I then return to image-canvas size and increase the canvas to 110%. I center the image and click resize. I then open a white layer and place it below the picture. I now have a frame that when carved will be the highest point of the picture (It makes cutting the picture from the board easier and straighter for me, plus it creates a nice frame for the wall) I then save the .xcf file as a new file so my original work is preserved and I export it as a jpeg. In photoVcarve I import it and set the size, use 12% (It seems 500-700 lines are a good number), use a tapered 1/8 inch ballnose from Precise bits (They have been very helpful giving me advice even when they talk over my head). I set the code and check the time- I don't like cuts more then three hours- This dog of mine took about 2 hours cutting a piece 6.5" by about 7.4 inches. A note on wood. To do these you cant have a wood with a lot of grain or it detracts from the picture. It also needs to be a very hard wood- I tried Poplar, redwood, oak, Aspen, Maple and Hickory. I like Hickory because it holds a good edge and the boards generally don't have a lot of grain. They are readily available at Menards for $14 a board- 3/4" by 4' by 7 1/4". I get 4-5 cuts out of a board. (I also love maple but it is expensive and I read it tends to burn). I hope this helps and can certainly go into more detail if anyone wants it.

BDM
Vectric Craftsman
Posts: 167
Joined: Tue Jan 04, 2011 3:52 pm
Location: S.E. Michigan

Re: Carving Bas Reliefs of Photos

Post by BDM »

A lot of times, people over think the process. Our brains/eyes are constantly converting 2D objects (like a photograph) to 3D without us fully realizing it. The same goes for PVC. Many times, from a distance you can't tell if the black is carved deeper than the white or vice versa, unless you get up really close. So unless the point of your project is to have something that people can run their hands over, there is quite a bit of latitude in how you do it and still get something that is readily obvious what it is. Even using pretty shallow cutting depths, you can get carvings that fool people into thinking it is much deeper, especially if you are good at post processing with stains and paints. The dog is kind of an extreme example, but even then I think if you took a higher quality photo and changed the lighting, you wouldn't have to spend a lot of time (if any) with gimp and other software.

User avatar
Ms Wolffie
Vectric Wizard
Posts: 2695
Joined: Sat Mar 31, 2012 10:41 pm
Model of CNC Machine: Blue Elephant 1325, Shark HD Pro
Location: Tully Heads, Wet Tropics, Queensland, Australia

Re: Carving Bas Reliefs of Photos

Post by Ms Wolffie »

M Rabin
Your information is great but please use paragraphs.
My old eyes get lost trying to follow line by line in such a long document and then I have to start all over again before I finally give up reading it.
Cheers
Wolffie
Cheers
Wolffie

Whatshammacallit
Cut3D, VCarvePro 6.5, Aspire4, PhotoVCarve, Corel Graphics Suite X6

Win Brayer
Posts: 44
Joined: Sun Jan 06, 2013 11:16 pm
Model of CNC Machine: Mako CNC Shark HD

Re: Carving Bas Reliefs of Photos

Post by Win Brayer »

I have just started using GIMP. Does a great job of making backgrounds transparent. However, I was not able to follow the above process. Can you do 1 thru x steps indicating the actual buttons/selections in GIMP and PhotoVCarve?

M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Re: Carving Bas Reliefs of Photos

Post by M Rabin »

Unfortunately it is very extensive to go through each step. I am preparing a power point for the Shark Club in Milwaukee. I am hoping to present it there. I have taken screen shots of each step as I prepare a picture (there are so far 45 pictures.... far too many to post here) and would be happy to share them with you or communicate with you outside this forum but I don't know how.

Fleming
Vectric Wizard
Posts: 400
Joined: Tue Oct 28, 2008 3:41 pm

Re: Carving Bas Reliefs of Photos

Post by Fleming »

I would also love to see your presentation when you get it done.
Perhaps putting it all into pdf format and then compressing it might work?

Thanks,

Paul
Cobblewood Carver

M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Re: Carving Bas Reliefs of Photos

Post by M Rabin »

Sorry I haven't replied but I am creating a Power Point presentation and did screen shots. Unfortunately screen shots aren't really good enough so I did a screen capture of converting a picture. The file is much to large (45 minutes) to send via email or text. If you have drop box I would be happy to drop it to both of you but I need your information so I can set up a shared folder.

M Rabin
Posts: 10
Joined: Tue Oct 22, 2013 1:00 am
Model of CNC Machine: shark

Re: Carving Bas Reliefs of Photos

Post by M Rabin »

I was also remiss in not answering one of the above posts. Taking a high quality photo with neutral lighting helps but a dogs nose is black no matter how good a photograph you take and will always be sunken when you do a carving hence the need for GIMP to heightmap and bring the nose out instead of in. Fogs are an extreme example but if a technique wont work with the extreme that it isn't a very good technique. Babies are easy but I didn't want to be limited to them.

Post Reply