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Review the scanning techniques graphics professionals and photographers use, while delving into workflow considerations and the advanced image-quality controls available in most scanning software. Author Taz Tally explains the core concepts, such as how resolution and interpolation affect scans; introduces the industry-standard SilverFast scanning software; and shares the settings to achieve the best results from a scan. The course also covers keeping your scanner and its parts clean and free of dust, and includes a variety of start-to-finish scanning tasks.
In this exercise, we're going to scan a piece of complex line art and then we compare this image of the octopus with a feather image that we did in the previous movie, we see there is a world of difference between them. With a feather, that image is all about reproduction of edges. This image is all about reproduction of the detail that's on the inside of the octopus. Unlike the feather where it really didn't make too much difference as to what the outline of that image was in terms of the dimension because we intended to convert it to vectors anyway, here with a complex image, we may indeed want to pay better attention or more attention to our actual output dimensions.
If you had a very small image, and you intend to use it at a much larger dimension, this is the place to scale it because you're working with original raw data and particularly if you're capturing more than 8 bits per pixel on your image. So this original image is about 5x7 and we are going to reproduce it at 5x7. But if we wanted to go to 10x14, we can certainly do that, and the scanner is the best place to do it rather than in Photoshop, because this image is not going to go to vectors. It's going to stay in pixels, and because pixel-based images are all about the detail, whereas vector-based images are all about the edges.
So we'll create a 7x5 outline of our frame and then we're going to choose our scan type. Unlike the simple line art image in which we use 1-bit black and white, for this one, to get our detail, we are going to go with an 8-bit grayscale image. True enough, you can choose 16-bit and deliver 16-bit from the scanner. I think we are going to be just fine going 16-bit to 8-bit. And again, you can test those two with your editing and your output devices to see if there's a difference. We are not going to do any filtering, no sharpening, we could sharpen it here, but this is absolutely one of those images where if I am going to apply Sharpening, I am going to do it later, I am going to do it in Photoshop, and I will show you why.
Now, we could just do a scan, and we'd probably be okay, but we might actually want to just use the image the way it's scanned, so we might as well optimize it a little bit. So let's go up to our Histogram tool as it's called in SilverFast similar to what we have in Levels in Photoshop. Notice that we've got some blank space on the highlight, and on the shadow end. Watch the background over here, this is a great way to remove background like if you've got a little bit of a gray background, or a light-colored background, you can knock that background completely out of it, so you just end up with the line art. Boom! Get rid of the paper, get rid of, or if it's a dirty image, or it's on a piece of low-quality paper, you can just completely take the paper out of the picture, which is great.
With that one simple move right there, you can make your life a whole heck of lot easier. This works great on faxes, on low- quality paper, you can get rid of background just by moving that highlight in. On the shadow, just increase the contrast of this a little bit. We don't want to move way up in to the data, and I will show you why in just a moment when we get into Photoshop. We'll just move up kind of to the beginning of the data, and there we go! Notice the contrast of that is much improved now. So with just a little bit of an adjustment, just a little touch up of the histogram, we've knocked out the background and improved the contrast of the image.
All right, now let's discuss Resolution. With a simple line art image that we take the vectors, if the scanner has an optical resolution of say 1200 pixels per inch, we've demonstrated I think conclusively that 600 is just fine. But in images like this where we have got lots of detail, then we're going to go with the full 1200. We're going to take this all the way up, but we don't need more than that. We really don't.I haven't scanned a line art image that ever needed more than 1200 pixels per inch. They may exist, but I haven't found them. Notice that already we are going to have a 48 MB file here. But 1200 is good given lots of detail, and lots of grayscale values to work with.
So 16 to 8-bit, 1200 pixels per inch, get the frame set, name the file, logical name, bit depth and resolution and click Scan. Save this out as a TIFF of course, no compression and we could save it out as a JPEG, but I never do, because remember, the TIFF is completely uncompressed. There is no sub-sampling or down- sampling, or compression of your data at all. This scan is going to take a lot longer than the simple line art scan that we did. Why? Because with a simple line art scan, one, we're at 600 pixels per inch, so it's going to be one-quarter of the amount of data just in terms of resolution and here we've gone from 1-bit to 16-bit in terms of the capture.
So that's 16 times as long. So it really is going to take a lot longer to create the scan. It will be worth in terms of the detail that we have inside this image. So the scanner is going through two processes. one is scanning at 1200, and then the second one is capturing at 16-bit and then it's going to convert it to 8-bit when it gets all done with the scan, and that's why we end up with such a high- quality 8 bits per pixel in terms of the grayscale value on our images. All right, So here we have our octopus, our 8-bit octopus delivered to us and just one more comparison, and notice the difference between these two pieces of line art, we have the edge-based line art which is simple and then the detailed line art which has all this complexity in it.
All right, So let's toss our feather and just focus on the octopus for now. What I'd like to do is I'd like to zoom in, so you can take a look and see what's here. When we zoom way in there, compared to looking at like this where everything looks like a small hard dot, in fact, they're really not small hard dots at all, there is good continuous toned grayscale, and gradational edges in this image. And because we did that little bit of adjustment in the histogram, we end up with really nice high contrast image with a nice white background, and if we bring up our Info tool for instance and we look at the background, it's very, very little grayscale value there at all.
If we send this to print, it won't reproduce as a grayscale value at all, and then if we zoom in on the image, we see we get lots of gradational pixels, gradational values to work with. This is the beauty, one of the beauties of working in capturing an 8-bit grayscale. Now first, a word about print. if we don't do anything else to this image, the advantages of having it an 8-bit grayscale versus 1-bit black and white is this image is going to print and look much better as a grayscale image than it will as a 1-bit black and white image. Some people will be tempted to scan this in 1200 and 1-bit black and white to get all those hard edges.
But when you print those hard edges with just black and white pixels, it looks rough. It doesn't have the same quality, and texture to it that this does. So I rarely if ever will take an image like this, and convert it in a 1-bit black and white. Some cases like if I just want to use it for a fax, I can do that. So let's go through a couple of adjustments here inside of Photoshop now that we've got this data, and I am just going to do some duplicates. The first thing that I might do is just go ahead and just take this to black and white, and notice that this is a 1- bit grayscale image, so it's 8-bits per pixel, and I will just put the channels out there just so you can keep track of what's going on here.
Then let's go Image>Mode and go to Bitmap. There is a couple of ways we can do this. So we can go, I hate the word Bitmap. It's 1-bit black and white. We can take this image and just use a 50 % Threshold and then just click, boom! And notice how much harder that is. Let me back up, there is the grayscale, there's the black and white. Now, let's go back to the grayscale, zoom in a little bit, and go 1-bit black and white. See you end up with those hard edges, and on screen it looks sharper and then actually, if I were going to send this as a fax, this is a perfect image to re-create this as a fax because on a fax, you don't want any grayscale, you want black, you want white.
So if I were to use this for my fax logo, that's how I would go. There are some other things we can do here. We're going to keep this one as grayscale for now, and I am going to zoom up just a little bit, and I am going to bring up my Layers panel, and I am going to get rid of the Channels panel just for now, so we don't have too much complexity up here. Let's go to Curves and notice what we can do with Curves.
We can do this in Levels as well, but I like to do it in Curves because we have control of all the mid tones. I can take and I can control how much of this is black and how much of this is white by moving the Highlight & Shadow sliders like this. So that's one thing you can do. So we can make it darker, and then make it darker still, and lighter. We are treating it like it's a continuous toned grayscale image. Why? Well, basically because it is. So we can make adjustments like with curves and levels. Typically, you'll want to look at this at 100%, all zoomed in, you can see exactly what's going on, and see how you are increasing, decreasing the thickness of those edges.
This is what the grayscale values allow you to do inside your image. So we could even not even adjust the highlights and shadows, and just come in here and we can increase and decrease the thickness of those edges by just doing this. See all the editability you get. If you scan this in 1-bit black and white, you will never have that capability. So I am going to just lighten it just a little bit, so it gives us a lighter version. Notice that I'm using an adjustment layer, so that we have full editability of our file. Notice we have lighten this a little bit, taken out some of the darkness of the image, so it will print on a low -quality device. There we go! It's another version.
The adjustment layer gives us full editability as nondestructive editing. One of our choice here and these are just some among many, and we are going to call this one the Sharpen Version. I am sure you say, really cool! Watch what we can do with a continuous toned grayscale image like this with a Sharpening Filter. All right, Come up here, go to Sharpen, go to Unsharp Mask, and I can take this to 500% and notice what that does to the sharpness of the image.
See this is why we didn't want to do the sharpness, and we go to 100% so you can see what's going on. This is why we didn't want to sharpen during the scan because we have full control of this here. Now, I am going to back out, so you can see the whole image and watch. With the Radius, I am going to go from 2 to 10, from 10 to 25, from 25 to 50. I can get full creative control over what this puppy looks like. Again, let's zoom in, and take it through that same process. 10, 25, 50.
That would be another great fax image, and it would also print very well, because although it looks like pure black and white, notice you still have a little bit of a grayscale value on the edge. So when it prints, you're going to end up with basically what is an anti-alias print version and it's going to look really nice. You are going to have that nice softness, just a tiny little bit of softness, but with a really high detailed image. Point being is that when you scan an 8 -bit grayscale or the detail line art images, you can bring it into Photoshop and just basically have your way with it.
So there is working with detail line art, and just a few tips and tricks on how you can work with it in Photoshop and I am sure you will come up with your own as well.
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