Image editing includes the process of changing the image, be it a digital photo, a traditional photo-chemical photo, or an illustration. Traditional analog image editing is known as photo retouching, using tools like airbrush to modify photos, or edit illustrations with traditional art media. Graphics software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, and 3D modelers, are key tools that users can use to manipulate, enhance, and transform images. Many image editing programs are also used to create or create computer art from scratch.
Video Image editing
Image editing basics
Raster images are stored on a computer in the form of a picture element, or pixel lattice. This pixel contains image color and brightness information. The image editor can change the pixels to enhance the image in many ways. Pixels can be changed as groups, or individually, by powerful algorithms in the image editor. This article mostly refers to the bitmap graphics editor, which is often used to change other raster photos and graphics. However, vector graphics software, such as Adobe Illustrator, CorelDRAW, Xara Designer Pro, PixelStyle Photo Editor, Inkscape or Vectr, are used to create and modify vector images, stored as line descriptions, Benezier curves, and text instead. pixels. It is easier to rasterize vector images than to vectorize raster images; how to make vectorization of raster images is the focus of much research in the field of computer vision. Vector images can be modified more easily, because they contain descriptions of forms for easy rearrangement. They are also scalable, rasterizable at any resolution.
Maps Image editing
Automatic image enhancement
Camera or computer image editing programs often offer basic automated image enhancement features that improve color hue and brightness imbalance and other image editing features, such as red-eye removal, sharpness adjustment, zoom and auto-cutting features. This is called automatic because it generally happens without user interaction or is offered with a single click of a button or mouse button or by selecting an option from the menu. In addition, some automated editing features offer a combination of editing actions with little or no user interaction.
Digital data compression
Many image file formats use data compression to reduce file size and save storage space. Digital compression of images can occur in the camera, or can be performed on a computer with an image editor. When images are saved in JPEG format, compression has occurred. Both cameras and computer programs allow the user to adjust the compression level.
Some compression algorithms, such as those used in the PNG file format, are lossless , which means no information is lost when the file is saved. In contrast, the JPEG file format uses the lossy compression algorithm in which the greater the compression, the more information it loses, ultimately reducing image quality or irreversible detail. JPEG uses knowledge of how the human brain and eyes feel color to make this loss of detail less noticeable.
Features image editor
Below are some of the most widely used capabilities of a better graphics manipulation program. This list is by no means all inclusive. There are many options related to most of these features.
Options
One of the prerequisites for many of the applications mentioned below is the method of selecting parts of an image, so applying changes selectively without affecting the whole image. Most graphics programs have several ways to accomplish this, such as:
- marquee tool to select rectangles or other polygon-shaped areas,
- lasso tool for free area selection,
- a magic wand that selects an object or region in an image determined by the proximity of color or luminescence,
- vector-based pen tool,
as well as more sophisticated facilities such as edge detection, masking, alpha composing, and color and channel based extraction. The border of the selected area in an image is often animated by the effect of marching ants to help the user differentiate the selection limits from the background image.
Layers
Another feature common to many graphical applications is Layers, which are analogous to transparent acetate sheets (each containing separate elements forming a composite image), stacked on top of each other, each capable of being individually positioned, altered and mixed with a layer below, without affecting any element in another layer. This is a fundamental workflow that has become the norm for most programs on the market today, and allows maximum flexibility for users while maintaining non-destructive editing principles and ease of use.
Image size change
The image editor can resize images in a process that is often called the image scale, making it larger, or smaller. High-resolution image cameras can produce large images that are often reduced in size for Internet use. The image editor program uses a mathematical process called resampling to calculate a new pixel value that is either larger or smaller than the original pixel value. Images for Internet use remain small, say 640 x 480 pixels which would be equal to 0.3 megapixels.
Crop image
Digital Editor is used to crop the image. Cut create a new image by selecting the desired rectangular portion of the image being cropped. The unwanted portion of the image is removed. Trimming the image does not reduce the resolution of the cut area. The best results are obtained when the original image has a high resolution. The main reason for the cut is to improve the composition of the image in the new image.
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Using the selection tool, the outline of the image or element in the image is tracked/selected, and then the background is deleted. Depending on how complicated these "edges" might be, it's harder to do. For example, individual hair can require a lot of work. Therefore the use of "green screen" (chroma key) technique allows one to easily remove the background.
Histogram
The image editor has the provision to create an image histogram of the image being edited. The histogram plots the number of pixels in the image (vertical axis) with a certain brightness value (horizontal axis). The algorithm in a digital editor allows the user to visually adjust the brightness value of each pixel and dynamically display the results when the adjustment is made. Improvements in brightness and contrast of images can be obtained.
Noise reduction
The image editor can display a number of algorithms that can add or remove noise on an image. Some JPEG artifacts can be removed; dust and scratches can be removed and the picture can be not speckled. Noise reduction only predicts the scene state without noise and is not a substitute for getting a "cleaner" image. Excessive noise reduction leads to loss of detail, and its application is therefore subject to trade-offs between the undesirability of the noise itself and from the reduction artifacts.
Noise tends to strike an image when a photo is taken in a low light setting. New images can be given an 'antiqued' effect by adding a uniform monochrome noise.
Removal of undesirable elements
Most image editors can be used to remove unwanted branches, etc., using the "clone" tool. Removing these annoying elements attracts focus to the subject, improving the overall composition.
Selective color changes
Some image editors have the ability to swap colors to selectively change the color of certain items in an image, remembering that the selected item is within a certain color range.
Image orientation
The image editor is able to change the image to be rotated in any direction and at any level. Mirror images can be made and images can be reversed horizontally or vertically flopped. A small rotation of several degrees is often enough to equate the horizon, the correct verticality (of a building, for example), or both. The rotated image usually requires pruning afterwards, to remove the resulting gap on the edges of the image.
Prespective controls and distortions
Some image editors allow users to distort (or "change") image shapes. While this may also be useful for special effects, it is the preferred method of correcting typical perspective distortions resulting from photographs taken at an angled angle to the square subjects. Care is required when performing this task, since the images are reprocessed using adjacent pixel interpolation, which may reduce the overall image definition. The effect mimics the use of perspective lens lenses, which achieve similar correction in the camera without losing the definition.
Lens correction
The photo manipulation package has a function to correct images for various lens distortions including bearing pads, fisheye and barrel distortion. Correction in many cases is fine, but can improve the appearance of some photos.
Improved image
In computer graphics, the process of improving the quality of images is stored digitally by manipulating images with software. It's easy enough, for example, to make the image lighter or darker, or to increase or decrease the contrast. Advanced photo enhancement software also supports many filters to change the image in various ways. Special programs for image enhancement are sometimes called image editors.
Sharpen and soften images
Graphics programs can be used to sharpen and blur images in various ways, such as masking or invisible decolutions. Portraits often look more pleasurable when diluted selectively (especially skin and background) to make the subject stand out. This can be accomplished with a camera using a large aperture, or in the image editor by making a selection and then blurring it. Edge Improvement is a very common technique used to make images look sharper, although purists frown on the results as seeming unnatural.
Another form of sharpening the image involves a form of contrast. This is done by searching for the average color of pixels around each pixel within a certain radius, and then comparing that pixel of that average color. This effect makes the image appear more clear, it seems to add detail. An example of this effect can be seen to the right. It's widely used in the printing and photography industry to improve local contrast and sharpen images.
Selecting and merging images
Many graphics applications are able to combine one or more individual images into one file. The orientation and placement of each image can be controlled.
When selecting raster images that are not rectangular, an edge separator is required from the background, also known as silhouetting. This is a digital analog cut off image from a physical image. Clipping paths can be used to add silhouette images to vector graphics or page layout files that retain vector data. Alpha composition allows transparent transparent edges when selecting images. There are a number of ways to silhouette images with soft edges, including selecting a picture or background by sampling the same color, selecting edges with raster tracing, or changing the clipping path to raster selection. Once the image is selected, it can be copied and pasted to other parts of the same file, or to a separate file. The selection can also be stored in what is known as the alpha channel.
A popular way to create composite images is to use a transparent layer. The background image is used as the bottom layer, and the image with the part to be added is placed on the layer above it. Using the image mask layer, all the merged sections are hidden from the layer, giving the impression that these sections have been added to the background layer. Merging in this way preserves all pixel data in both layers to make it easier to enable future changes in new composite images.
Slicing image
A newer tool in digital image editing software is an image slicer. The image section for graphical user interface or web pages is easily sliced, labeled, and stored separately from the entire image so that parts can be handled individually by the display media. This is useful for enabling dynamic exchange through interactivity or animating parts of an image in the final presentation.
Special effects
The image editor usually has a list of special effects that can create unusual results. Images can be skewed and distorted in various ways. Special effects scores can be applied to images that include various forms of distortion, artistic effects, geometric transformation and texture effects, or a combination thereof.
Stamp Clone Tool
The Clone Stamp Tool selects and samples your drawing area and then uses this pixel to paint over any mark. The Clone Stamp tool works like a brush so you can resize, allowing cloning from just one pixel to hundreds. You can change the opacity to produce a smooth clone effect. Also, there is a choice between Clone align or Clone non-align sample area. In Photoshop this tool is called Clone Stamp, but it can also be called Rubber Stamp tool.
Change the color depth
Probably, using the software, to change the color depth of the image. Common color depths are 2, 4, 16, 256, 65,536 and 16.7 million colors. JPEG and PNG image formats are capable of storing 16.7 million colors (equal to 256 lighting values ​​per channel color). In addition, grayscale images of 8 bits or less can be created, usually through conversion and down-sampling of full-color images. Gray conversion is useful for dramatically reducing file size when original photo prints are monochrome, but color tint has been introduced due to the effects of aging.
Contrast changes and brights
Image editors have the provision to simultaneously change the contrast of images and brighten or darken the image. Less bright images can often be improved by using this feature. Recent advances have enabled smoother exposure correction where only pixels below a certain bright luminosity threshold, thus brightening a less bright image without affecting the rest of the image. The exact transformations applied to each color channel can vary from editor to editor. GIMP applies the following formula:
where value is the input color value in the range 0..1 and brightness and contrast is in the range -1..1.
Gamma correction
In addition to the ability to change the brightness and/or contrast of images in non-linear mode, the current image editor provides an opportunity to manipulate the image's gamma value.
Gamma correction is useful for bringing details that will be hard to see in most computer monitors from the shadows. In some image editing software, this is called a "curve", usually a tool found in the color menu, and no reference to "gamma" is used anywhere in program or program documentation. Strictly speaking, curve tools usually do more than simple gamma correction, because one can build complex curves with multiple inflection points, but when no special gamma correction tool is provided, it can achieve the same effect.
Color settings
Color images can be changed in various ways. Colors can fade in and out, and tones can be changed using curves or other tools. The color balance can be improved, which is important if the picture is taken indoors with a daylight film, or shot in the camera with the wrong white balance settings. Special effects, such as sepia tones and gray scale, can be added to the image. In addition, more complex procedures such as color channel mixing are possible using more sophisticated graphics editors.
The red-eye effect, which occurs when a flash image is taken when the pupil is too wide open (so the light from the flash coming into the eye through the pupil reflects the fundus at the back of the eyeball), can also be removed at this stage.
Dynamic mixing
Advanced Dynamic Blending is a concept introduced by photographer Elia Locardi on his blog Blame The Monkey to describe the photographic process capturing some of the enclosed exposures of the land or city landscape over a given time span in a natural or artificial lighting environment that is changing. Once retrieved, the exposure bracket is manually merged into a single High Dynamic Range image using post-processing software. Dynamic Blending images serves to display consolidation moments. This means that while the final image may be a combination of time spans, it visually appears to represent an instant.
Controlling print size and digital image quality requires an understanding of the pixel-by-inch (ppi) variables stored in image files and sometimes used to control the size of the printed image. In the Adobe Photoshop Image Size dialog, the image editor allows the user to manipulate both pixel dimensions and image size on printed documents. These parameters work together to produce a print image of the desired size and quality. Pixels per inch of image, pixels per inch of computer monitor, and dots per inch on related print documents, but used very differently. The Image Size dialog can be used as an image calculator. For example, a drawing of 1600 ÃÆ'â € "1200 with a resolution of 200 ppi will result in a 8 × 6 × in. An image equivalent to 400 ppi will result in a 4 ÃÆ'â € "3 inch print image. Change the resolution to 800 ppi, and the same image is now printed at 2 ÃÆ'â € "1.5Ã, inch. The three printed images contain the same data (1600 × 1200 pixels), but the pixels are closer to smaller prints, so smaller images will potentially look sharp when the bigger ones do not. The image quality will also depend on the capabilities of the printer.
Warping
See also
References
Source of the article : Wikipedia
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