Here's a look back at the original. When director Steven Spielberg and author Michael Crichton were working on a screenplay that would eventually become the television series ER, Spielberg asked the writer about the plans for his next book.
In fact it works in just about the Digital composite in special effects way. For examples which show how this is related to blur see, Image Processing By Interpolation and Extrapolation. For example lets blur a simple image then attempt to sharpen it again to remove the blur.
Particularly notice the extra thickening that resulted at the corner of the two lines at the very top of the image, as well and the near disappearance of the thin lines. Even repeating the operation or increasing the size of the area of the sharpen will not help return the image back to the exact original as you have basically lost the finer detail from the image blurring.
However the macro detail can be recovered quite well. It is sharpening algorithms which can recover of finer detail in a blurred, or heavily zoomed image, that makes big money in software packages used by police forces, astronomers, and government spy agencies.
Unsharp Images Under Construction Both the " -sharpen ", and " -unsharp " operators, work using the exact same technique of subtracting a blur from the original image. For the internal details of how both " -sharpen ", and " -unsharp " actually work see Unsharpen Convolution.
It takes the difference edge result as above, i.
Or it could be just some slight differences elsewhere in the IM implementation. If one blends less with the original, one gets less sharpening. The thresholding in my scripts is done differently and for a different purpose. Sharpen using de-convolution There is a technique of using de-convolution division in a Fast-Fourier generated frequency form of imagesThis works best when the exact 'blur' that was applied to the original image is known, or calculated in some way.
Generating Shadows The " -shadow " operator is a advanced operator that was developed with the IM example pages. Basically it represents a very complex blur and re-coloring of transparency shape of the given image. This is an operation that IM users performed all the time, but required a good deal of knowledge to figure how to achieve correctly.
The operator will take an image usually a clone, and may already have some transparency and convert it into a shadow image that can then be positioned under the original image at given offset, generally by using the special Layer Merge operator.
Here for example is a standard method of shadowing an existing image, using a navy shadow color to match this web page. You can even zero the blur 'sigma' value and create a hard shadow, but semi-transparent shadow. See Shadows and the Offset Problem for alternative techniques.
The Layers Merge method was added to IM v6. Before this you would need to use the similar layer flattening operator " -mosaic " instead.
However this operator has problems see next. Shaped Shadows Now " -shadow " was designed with shaped images in mind, and this is the reason for its complexity. For example here is a typical shadowed font. It uses a special ' DstOver ' composition method so as to avoid the need to swap the order of the two images.
Shadows and the Offset Problem The problem with shadow is that a blurry shadow extends in all directions.
To compensate the " -shadow " operator enlarges the actual original image by adding a border 2 times the size of the blur 'sigma' value given. That is if you blur a shadow using 'x3', it will enlarge the image by 12 pixels 2 times 3 pixels on every side.
To compensate for this enlargement, a shadow image is also given an appropriate negative Virtual Canvas Offset so that it will be positioned correctly relative to the image being shadowed. For a normal image that means the shadow image generated will have a negative offset.
This however generates a problem when your IM does not have a the " -layers " method 'merge' available. For example here we try to add a shadow on the left side, of the image as if a light shone from the upper right.
One solution is to add an initial offset to the original image so the resulting shadow images offset will not be negative. This removes any negative offsets before you " -mosaic " them together.
Note the use of a '! However space of about 'sigma'-'offset' usually produces an acceptable level of clipping. Another alternative is to expand the original image so as to make enough room for the final shadow. This is the BEST way of handling shadows, while preserving the images original location on the virtual canvas.
For example here I pad out the original image with some extra space for the shadow, and then underlay the shadow image directly.
I included a border in the displayed image result so that you can see that the final image remains centered in the 'padded' image. Padding can be asymmetrical to reduce space, but typically a symmetrical padding like the above is used for convenience.Positioning The Overlay Image Composite Geometry/Gravity Settings In normal Alpha Composition the "-geometry" setting is used with "-gravity" to position the source image relative to the destination alphabetnyc.com these settings is covered in great detail in Image Positioning using Gravity..
Note that the size component of "-geometry" is special in that it will Resize an Image (geometry). About Guitars. With so many options available in the world today, buying a guitar that perfectly represents your own style, tastes, and attitude has never been easier. iv Digital Visual Effects & Compositing Acknowledgments I would like to begin by giving special thanks to my good friend William Vaughan.
William is, by far, the most talented artist I’ve ever met. Back in the day, filmmakers used matte paintings, miniature models and trick photography to achieve impossible looking cinematic effects.
Today, Hollywood has nearly perfected the art and application of computer-generated imagery (CGI) in movies and TV shows. It was a major special effect in the film - the Cain cyborg was designed and co-created by legendary special-effects animator Phil Tippett, with: a full-sized robot prop (head and torso) eight fully articulated, intricately-made, one foot-tall stop-motion puppets.
Special Effects for Composite Photography Class Description In this class, we will explore a variety of special effects that can add that polished look to your compositing work%(23).
More complex effects are often easier to composite in a digital arena. However, show me a "meat and potatoes" optical--a fade, dissolve or three-image montage--which is not made more complicated and expensive by the conversion process, and I'll eat my beret. Type or paste a DOI name into the text box. Click Go. Your browser will take you to a Web page (URL) associated with that DOI name. Send questions or comments to doi. The Visual Effects Art and Design program focuses on providing graduates with a solid foundation in the technical and artistic skills needed to be successful in the visual effects.