Scanning detailed line art

In this video, I would like to show you how using the Manual Scanner interface and tools to capture detailed line art. Let's begin our discussion by looking at our detailed line art image and just talk about what are some of our challenges and goals are. I have already done a prescan, as you can see it's a good place to usually start the scanning process to just set our frame and then enlarge our image by clicking on the Magnifying Glass and take a look and discuss this image just a little bit. With simple line art, it's 100% about capturing the edge and reproducing the edge, but with detailed line art, this image is more about capturing all of its details that's in here.

So we could capture this image as a simple black and white line art image, clicking up here on the Bit depth, but notice what happens. A lot of the detail gets lost because the lighter grayscale values are being pushed to white. So it really can be much better off capturing this in 8 bit mode. The next thing to address is the contrast. When we look at this image we think, okay we have got black areas here and white areas here. But do we really? I am going to go ahead and close this tool and let's back off. I am going to click on our Magnifying Glass to zoom back down, and I want to bring out a tool that I mentioned earlier in the chapter called the Densitometer, and I am just going to go ahead and float that over here.

This is going to allow us to take a look at what the background values of the paper is, and notice when I move my cursor over here, oh my gosh! Look at there is 7% grayscale in there, 6%, 5%; this is not uncommon. In fact, most papers even very high- quality papers typically at least 5% grayscale. If we want the highest quality scan, we would like to knock most of that texture out and end up with just the octopus. And what I am going to do here is I am going to set a couple of grayscale points, and to do this, I will hold down my Shift+Option key on the Mac or Shift+Alt on Windows and I am going to put one there and on the inside of the octopus as well.

And notice both of those are 8% gray, and just to review, the K value is percent black, and K is like in CMYK, K stands for Black. Notice these are 8% grayscale in that background. So if we just scan it like this, there is really not as much contrast between the line art and the background as we could get. So what we are going to do is knock out the background without affecting the actual grayscale values in the octopus. And the tool we are going to use to do this is the Histogram tool. And if we want to, we can move that Histogram tool, we can float that over here as well so that we can snug it right up and we don't have to move our mouse around quite so much.

And the Histogram tool shows us a distribution of grayscale values in the image, with the right side being the Highlight end and then the left side being the Shadow end and of course, this is the Midtone. And learning to evaluate histograms could be enormously helpful not only with line art but all sorts of continuous tone images in guiding us as to how we want to adjust our images. And here the Histogram tells the whole story. Look the white highlight end is out here, and look, this big spike right here is the background paper. So we can see that this big spike is well short of the actual highlight which is why it has 8-10% grayscale.

Well, what we can do to adjust this is just take his highlight end while we are monitoring these K values here, and I am just going to pull this in, and this big spike is the background. And notice now we are down to 1% on the K values and then we move it all the way over here we get right to zero. I want to make sure I lose all of that background. So what I am going to do is I am just going to pull it all the way over to the beginning of that spike, so we know that the complete background is going to zero, all this data that we see here, all the ups and downs, that's all the grayscale that's part of the octopus.

And if we want to we can move this up to darken the Grayscale value of the black end of the octopus if we'd like to and that's fine to do. No problem. We could just leave it right there and typically to be honest with you, I would. Let me just show you a little bit more, I am going to go ahead and put this back over to here and I want to zoom in again, but in this case, I would like to zoom in and look at the detail just a little bit. Because if you are going to do everything during the scan, if you really don't want to work in Photoshop, then you might want to do this next move. And notice when we zoom in here, things are a little bit soft and if that's the case, you can just hit that Prescan button again, and SilverFast will perform another prescan.

What we are looking at here is the distribution of grayscale values and the interaction of the white and the black areas, and what we can do is we can change, there is the prescan and it came across our image and so we can see the open areas a little bit easier in the black areas. If you just want to do everything during the scan, you can adjust the Midtone here to either open up or close down the detail areas in the image. So we might decide, oh let's open it up just a little bit to make sure that the white areas in the image pop out from black areas.

And by the way, while we are here, let's just take a look at the impact of moving that shadow end. It just darkens everything up just a little bit, but doesn't fill in this area. You move it too far you could see how we lose some of the detail in the denser areas. So again, the Histogram could be such a great tool in guiding us as to how much and where we move and adjust our images. So there we go. There is adjusting the image. We have got a pure white background, we have got nice black areas in the dark areas of the detail. We've made sure we kept the open areas for the white, we are ready to go ahead and complete our scan.

I am going to click on the Demagnify button and I am going to pull my scan frame out to encompass the octopus, and then let's go up to our Scan dimensions dialog box and notice in the Expert settings down here, we can set a specific dimension if we want to. Probably not necessary in this case, but if we wanted to we could. I am just going to leave that as I have drawn it just qualitatively here, but we do want to discuss Resolution. Notice that we have 600 pixels per inch here which is a typesetting. That might be enough for this image, but if we got lots of high detail, I typically tended to go ahead up to 1200 pixels per inch, and 1200, because it's one-fourth the optical resolution of the scan, which is 4800.

You might ask, oh should we be using 2400 or 4800? It's way overkill. There are few images that require that sort of resolution on scanning, besides it makes huge files. So we'll go up to 1200. You might be able to get by with 600. It depends upon how much detail is in the image. I think that this image, particularly in this dense area right in here with the detail, when we scan at 1200, it's going to preserve more of that white area detail. All right! Then we will name the file and then we're going to put an underscore, and I always like to have the scan mode, which is Grayscale.

Then I always like to put the resolution. I like this three-part naming scheme because it tells me a lot about the image just looking at the file name. Finally, we'll make our file format choice, and if you listen to my riff on this, many times just bear with me. I always save my original scans out in high-quality uncompressed format, even if I intend to use this most of the time as a JPEG, I save the original scan out in high-quality format, either as a TIFF, or if I intend to work on this in .psd, which I often do. I fine-tune this in Photoshop. But a TIFF is a good choice for an overall high-quality, uncompressed format that you can use in a lot of circumstances and open and edit in a lot of image editing applications. All right! There we go.

So we are ready to scan. We will just go ahead and click the Scan button and notice you can monitor the scan process. If your scanner hasn't been used for a few minutes, it may have cooled down, so it will warm-up. You see it says Warming up, and then it will begin the scan process. You will notice, it's requiring a little bit more time because capturing four times as much information. And once the scan is complete, you can just click on this Open image button here and then SilverFast will direct whichever image editing application you have assigned to open TIFFs, and in my case, it's Photoshop.

You can see we have got a beautiful high contrast image. One final thing to discuss is notice that this image does have some type that was captured, we couldn't help because it was part of the scan frame. Typically my approach here is to edit this out in Photoshop and then set the type either separately in Photoshop with a font or in a Page Layout program. Typically type tends to fall apart a little bit. You can see this A down there. So that's a call that you have to make, and typically if you want to highest quality type, you will just reset it. So the last thing that I would do here in Photoshop is apply some sharpening at some point.

I typically like to save my sharpening for the post-scan area and usually apply to copies of the images. So there we go, capturing detailed line art using SilverFast 8.