Download a free trial version of Adobe Photoshop CS3. Unsharp masking Wikipedia. Unsharp masking applied to lower part of image. Unsharp masking USM is an image sharpening technique, often available in digital image processing software. The unsharp of the name derives from the fact that the technique uses a blurred, or unsharp, negative image to create a mask of the original image. The unsharped mask is then combined with the positive original image, creating an image that is less blurry than the original. The resulting image, although clearer, may be a less accurate representation of the images subject. In the context of signal processing, an unsharp mask is generally a linear or nonlinear filter that amplifies the high frequency components of a signal. Photographic unsharp maskingedit. Simplified principle of unsharp masking. The technique was first used in Germany during the 1. For the photographic process, a large format glass plate negative is contact copied onto a low contrast film or plate to create a positive image. However, the positive copy is made with the copy material in contact with the back of the original, rather than emulsion to emulsion, so it is blurred. After processing this blurred positive is replaced in contact with the back of the original negative. When light is passed through both negative and in register positive in an enlarger for example, the positive partially cancels some of the information in the negative. Photoshop, today is the most popular and profitable application that supports layers, filters, brushes, text, 3D objects, videos, etc. Photoshop is mainly. How to cut out things in Photoshop using the amazing tools in the mask panel, color range and select and mask without ever leaving the mask panel. Eric provides a Photoshop tutorial on making a photo booth type photo strip, and adds a template too The Plugin Site Photoshop plugins, Photoshop Elements plugins, Lightroom plugins, free plugins. Get Adobe Photoshop now at the Adobe Store. Find Photoshop CS4 tutorials and videos on our Photoshop CS4 Tutorials Page. Try before you buy. Download any Adobe. Because the positive has been blurred intentionally, only the low frequency blurred information is cancelled. In addition, the mask effectively reduces the dynamic range of the original negative. Thus, if the resulting enlarged image is recorded on contrasty photographic paper, the partial cancellation emphasizes the high spatial frequency fine detail information in the original, without loss of highlight or shadow detail. The resulting print appears more acute than one made without the unsharp mask its acutance is increased. In the photographic procedure, the amount of blurring can be controlled by changing the softness or hardness from point source to fully diffuse of the light source used for the initial unsharp mask exposure, while the strength of the effect can be controlled by changing the contrast and density i. For traditional photography, unsharp masking is usually used on monochrome materials special panchromatic soft working black and white films have been available for masking photographic colour transparencies. This has been especially useful to control the density range of a transparency intended for photomechanical reproduction. Digital unsharp maskingedit. Source image top. The same differencing principle is used in the unsharp masking tool in many digital imaging software packages, such as Adobe Photoshop and GIMP. The software applies a Gaussian blur to a copy of the original image and then compares it to the original. If the difference is greater than a user specified threshold setting, the images are in effect subtracted. The threshold control constrains sharpening to image elements that differ from each other above a certain size threshold, so that sharpening of small image details, such as photographic grain, can be suppressed. Digital unsharp masking is a flexible and powerful way to increase sharpness, especially in scanned images. Unfortunately, it may create unwanted conspicuous edge effects, or increase image noise. However, these effects can be used creatively, especially if a single channel of an RGB or Lab image is sharpened. Undesired effects can be reduced by using a maskparticularly one created by edge detectionto only apply sharpening to desired regions, sometimes termed smart sharpen. Typically three settings control digital unsharp masking Amount is listed as a percentage, and controls the magnitude of each overshoot how much darker and how much lighter the edge borders become. This can also be thought of as how much contrast is added at the edges. It does not affect the width of the edge rims. Radius affects the size of the edges to be enhanced or how wide the edge rims become, so a smaller radius enhances smaller scale detail. Higher Radius values can cause halos at the edges, a detectable faint light rim around objects. Fine detail needs a smaller Radius. Radius and Amount interact reducing one allows more of the other. Threshold controls the minimum brightness change that will be sharpened or how far apart adjacent tonal values have to be before the filter does anything. This lack of action is important to prevent smooth areas from becoming speckled. The threshold setting can be used to sharpen more pronounced edges, while leaving subtler edges untouched. Low values should sharpen more because fewer areas are excluded. Higher threshold values exclude areas of lower contrast. Various recommendations exist as to good starting values for these parameters,3 and the meaning may differ between implementations. Generally a radius of 0. It is also possible to implement USM manually, by creating a separate layer to act as the mask 2 this can be used to help understand how USM works, or for fine customization. The typical blending formula for unsharp masking is Sharpened Original Original Blurred Amount. Local contrast enhancementeditUnsharp masking may also be used with a large radius and a small amount such as 3. NewMaskBanner.jpg' alt='Photoshop Masking Images' title='Photoshop Masking Images' />USM can increase either sharpness or local contrast because these are both forms of increasing differences between values, increasing slopesharpness referring to very small scale high frequency differences, and contrast referring to larger scale low frequency differences. More powerful techniques for improving tonality are referred to as tone mapping. Comparison with deconvolutioneditFor image processing, deconvolution is the process of approximately inverting the process that caused an image to be blurred. Specifically, unsharp masking is a simple linear image operationa convolution by a kernel that is the Dirac delta minus a gaussian blur kernel. Deconvolution, on the other hand, is generally considered an ill posedinverse problem that is best solved by nonlinear approaches. While unsharp masking increases the apparent sharpness of an image in ignorance of the manner in which the image was acquired, deconvolution increases the apparent sharpness of an image, but based on information describing some of the likely origins of the distortions of the light path used in capturing the image it may therefore sometimes be preferred, where the cost in preparation time and per image computation time are offset by the increase in image clarity. With deconvolution, lost image detail may be approximately recoveredalthough it generally is impossible to verify that any recovered detail is accurate. Statistically, some level of correspondence between the sharpened images and the actual scenes being imaged can be attained. If the scenes to be captured in the future are similar enough to validated image scenes, then one can assess the degree to which recovered detail may be accurate. The improvement to image quality is often attractive, since the same validation issues are present even for un enhanced images. For deconvolution to be effective, all variables in the image scene and capturing device need to be modeled, including aperture, focal length, distance to subject, lens, and media refractive indices and geometries. HDR Style Results Using Layers in Photoshop. A Post By Darren Rowse. In this post Nathan Pask takes a look at a technique to get HDR Style Images Using Layers in Photoshop. There currently seems to be a lot of interest in HDR or similar processes. What is HDR Essentially, its about collecting a series of shots taken on a tripod at different exposures and allowing ber clever software to merge them together to make one supposedly perfectly exposed image. There are various types of software or plug ins such as Photoshop, Photomatrix or FDR Tools that make producing a HDR image fairly straight forward. Does the final result look pleasing to the eye The jury is out for a majority of it as far as Im concerned. Some images I think look fantastic, but others I feel have done nothing to enhance the subject. Its using process for processes sake. Being a professional retoucher for quite a few years, working for many demanding clients such as Cond Nast on Vogue, Bride Traveller magazines, the idea of retouching is about making an image more beautiful than it was to begin with. For the retouch to be successful, it needs to look seamless. It wants to look amazing, almost too good to be true, but with no tell tale signs of it having been manipulated. Granted, there is a place for artistic imagery, and perhaps some people who are producing HDR are just doing it for an artistic result, but I personally tend to lean towards the too good to be true style when producing an image like this. If you are not a fan of the results HDR give, but like the idea of it, read on. The process I am about to talk you through has essentially the same premise, but will give a more realistic finished result as per the example above. So to begin, you need to a good sturdy tripod. This is a little easier if you have an SLR camera, but it can also be done with a point and shoot if you can manually adjust your exposure. Mount your camera on the tripod and compose your image to your liking. It is important that when you take your images, your camera doesnt move. A handy tip if you dont have a remote control is to set your camera to its inbuilt timer and shoot with this as when you press the shutter you are shaking the camera ever so slightly and you will get a slightly blurry result. Every situation is different because your subject and light is different, but for the image above, I took a shot exposing for the water which was 4 seconds at f. I then took another shot exposing for the rock face and the trees which was 1 second at f. I then took another exposure for the sky which was 14 of a second at f. Ideally keep your f stop constant in this process and as you have it on a tripod you can afford to close down your f stopaperture to give you maximum depth of field throughout your image. The following process is using Adobe Photoshop. I am on a Mac using Photoshop CS3, but it doesnt matter which version you have. As long as it has layers, you are sorted. Download your images from your camera onto your computer. Once you have chosen your exposures you want to use, in my case 3, open them all in Photoshop so you can see them all side by side with your layers palette open on the side like this click images to open larger versions. It doesnt really matter, but I tend to use my darkest layer as my base just because its logical. With this in mind, select the middle exposed image. Head over to your layers palette and click and drag your layer icon and drop it on your darkest image. Then select your lighter image and repeat the process. Obviously, you can have as many imagesexposures as you like and continue this process till you have dragged all your exposures onto the one image. The more you have, the longer it will take to combine and the more complicated it will become, so choose your number of exposures wisely. You shouldnt really need any more than 3 or 4 exposures unless your subject is particularly complicated. Click back on your darker image that you have been dragging the layers on to. You should now have 3 layers in your palette and should look like this. You can close the other 2 images as these are no longer required. What you have left is one image open with your multiple layers, in my case 3, each layer containing exactly the same shot just taken with a different exposure all sandwiched on top of each other. You cant fully manipulate the bottom layer called Background, so select this layer, go up to the options at the top of the Layers palette and duplicate the layer. Its not essential to do this on this particular retouch, but its good to get into the habit of duplicating your original layer so you always have an untouched original just in case it all goes pear shaped or you want to refer back to it for some reason. Safety first Click on the little eye icon on the left hand side of the Background layer so it makes this particular layer invisible. You wont be needing this layer. Its just there as a back up. I tend to rename all my layers at this stage so it makes it easier to manage. Again, its not essential for this retouch, but getting into the practice of naming your layers appropriately is a good habit to get into. When you work on more complicated retouches that might have dozens of layers, it makes it much quicker when you can see easily which layer is which. So what are we going to do with these 3 layers We are going to mask out portions of each layer to allow elements from the layers underneath to show through eventually giving us 1 image formed out of 3. Lets start with our lightest exposed layer. In my case, I want this layer for the water and reeds only. Most of the trees and the sky are way too overexposed. Over to your Layers palette again, select your top layer your lightest layer and we want to add a layer mask to this layer. Go to the Layer menu at the top of your screen and select Layer maskReveal All. As a shortcut, you can also simply click on the little icon circled and it will do the same thing. The Tony Hawk Pc Collection New Packaging. For this particular layer mask I dont want to create a hard edge so we are going to use the brush tool to manually create our mask. Over to your layers palette again, make sure you have the mask part selected not the image icon when you click on the mask, it should have the broken black frame around it indicating that you have selected the mask. Making sure your colour is set to black if its not, click on the top colour square and change this 1. We are ready to maskWe are now going to paint with this tool creating a mask revealing some of the image below. In this case we want to get rid of the sky, rocks and most of the trees. Make sure the opacity on the brush is at 1. Use an appropriate sized large brush to get rid of a majority of it and when it comes to going around the water line I used a small brush and zoomed in so I could see a little better as I was masking. You should be able to see your middle exposure layer below coming through. You will also see your little mask icon on your layers palette will give you a preview of what you have just masked out. Keep going until you are satisfied. I will show you how to do a more accurate mask on the next layer. But this method we have just performed is a great way to do a quick mask. Once you are happy with your mask, select the layer below. Create a new layer mask as before but instead of using our brush tool on its own, this time we are going to make a selection first as we want the mask to be a little more defined around the edge of the cliffs.