A while back a customer sent me a photo that they where having problems reproducing on a black piece of granite. The problem was that the person they where engraving had a black shirt and hat. When the photo was processed the shirt and the hat turned white and thus did not engrave. This created a problem as it made the photo look funny as it appeared certain pieces of the photo where not there. This one stumped me for a bit but after some thought I figured it out. I have used this technique very successfully in a number of photos and if you are doing black granite than it is an excellent way to “fix” up a problem photo
Here is the Problem – We lose part of the Image as You Can See
As you can see in the above photo we are having a problem in that the dark hat and the dark shirt have all but disappeared. This is due to the fact that anything black in the image goes white when we have to invert the image – which is what we have to do here.
Here is the Fixed Image – Now Everything is There
As you can see from the above photo we have fixed he issue. Now the image is not being washed out by the black granite. The photo looks like a proper photo now. Lets take a look how we do this. Now before we go on you may start to get the idea that you can go in and fix the image with the contrast enhancement command. The problem with this command is that if I start to lighten up the darks I lighten up to much of the rest of the image. The whites will get blown out. This image can only be fixed via a “spot” adjustment. With the Clone command I can do this. Yes I know you could selectively select the area but heh for me that is to much work.
Here is My Image
Note: The first step in creating a successful image is to “knockout” the background which I did to this image. You can see that the background is completely white (gone).
Right Click on the Image
Right click on the image and select “Edit Bitmap”. This will open up the image into Corel PhotoPaint. You could just open up the image into PhotoPaint but this way everything will be saved back.
Select The Effect Command
From the Paint Icon leave your left mouse on the icon and let the menu flyout. Select the Effect (1) command
Select the Dodge and Burn Command
Select the Pull Down Menu (1) and you will get a number of commands. Select the Dodge and Burn tool (2).
Your Property Bar Will Change
Your property bar will change to reflect the commands for the Dodge and Burn tool. Click on the down arrow (1) to select the tool we need.
Select the Dodge Shadows
Dodge and image lightens it up. Burning and image darkens it up. We can adjust the Highlights, Shadows or the Midtones using either the Dodge or the Burn Tools. Because I want to lighten up a dark area I need to Dodge the shadows.
Adjust Your Nib SIze
We are going to paint over the dark areas with a brush. For this reason we need to setup our brush size. In this example i am going to use a nib size of 150. What size you set will depend on how fast you want to do the dodging of the image. However if the nib is to big than you may miss some areas.
My Nib is 150
My nib is round and the size is 150
Dodge (Lighten) Your Image
Now you can start dodging your image. Area 1 has been dodged and area 2 has not. You can see that area 1 is lighter than area 2. Remember when I invert the image it will go darker. Note: This is very important. You must dodge or burn all the image before you let go of the mouse. With the mouse depressed the effect will only happen once. Once you let go of the mouse again the effect will stat again. Thus it is important to do the whole area you want to dodge or burn so the effect looks consistent. If you make a mistake just press the ctrl and V key together to undo what you have done. Do not worry if you get a bit of the outside area you will not notice it in the engraving.
My First Pass is Done
I have done one pass over the shirt without letting go of the mouse
The Effect Applied Twice
I have gone over the shirt again once more.
The Hat and Shirt are Done
The hat and the shirt are done. You may think that I have gone over board a bit but the final effect is at the beginning. Remember a lot of the adjustments I do you would swear would look horrible on the finished product but they do not.
Convert to Grayscale
Now that our image is dodge we can not run our adjustment steps. First convert to gray by going to IMAGE (1) | CONVERT TO GRAYSCALE (2)
Sharpen the image
Next we need to Sharpen our image. Go to EFFECTS (1) | SHARPEN (2) | UNSHARP MASK (3).
UnSharp Mask Settings
For Black Granite which is a coarse material I like to use a Percentage of 500 (1) and a Radius of between 8 and 12 (2). Note make sure you zoom in on the image to see the adjustments. If you look at the image zoomed out it may look a little funny.
My Image Sharpened
Here is my image sharpened. You can see that I created a sharper distinction between shades of black.
Now Convert to Black and White
Next we need to convert out image to black and white. Go to IMAGE (1) | CONVERT TO BLACK AND WHITE (2)
My Image Converted
My image is converted to black and white. I have used the Stucki (1) error diffusion algorithm but you can use the Floyd Steinberg or Jarvis or Halftone. The original is on the left (2) and the converted image is on the right (3).
Invert the Image
We need to Invert our image. Go to IMAGE (1) | TRANSFORM (2) | INVERT (3)
My Final Image
Here is my final image. You can see that the shirt and hat are a mix of black and white and thus will have some areas that will engrave and some that do not.
Click on Finish Editing
To transfer my changes to the image back to the image in CorelDraw go to File (1) and Finish Editing (2)