Basic concepts of raster graphics
What is the difference between raster graphics and vector graphics?
All two-dimensional computer graphics can be divided into 2 large classes - vector and raster.
Vector graphics – a set of various geometric shapes and more complex objects consisting of straight lines, circular arcs and Bezier curves. The main distinguishing feature is the scalability of vector images without loss of quality. However, its capabilities are limited; in particular, it is impossible to create a photographic image using vector graphics.
Raster – a two-dimensional array of “squares” (pixels) of different colors, so small that when looking at a raster image we see not a set of pixels, but a complete picture.
Bitmap Options
A raster image is characterized by two important parameters - size and resolution.
Size – this is the dimension of the array, the number of pixels horizontally and vertically.
Permission – the number of pixels per inch (or other unit of measurement) of a printed image. Thus, resolution relates the size of a raster image in pixels to the physical size in inches or centimeters of the printed image. At the same time, the resolution does not in any way affect the display on the monitor screen.
Color representation systems
There are two main systems for representing color - RGB And CMYK . The first is used in computer monitors, the second - when printing on paper. Their main difference is that on the screen the absence of color is represented by black, on paper – by white. Accordingly, mixing the maximum number of colors on the screen corresponds to white, on paper - black. Thus, the systems are opposite to each other. RGB uses Red, Green, and Blue as its primary colors, while CMYK uses its opposite colors, Cyan, Magenta, and Yellow. However, on paper, due to the imperfection of printing devices, it is not possible to create a perfectly black color by mixing, so the CMYK system adds another base color - black.
Color depth is the number of bits that store color information per pixel in an image. The number of colors used in the image depends on this parameter. Let's say 8-bit color depth is 2^8 = 256 colors. The level of quality at which the human eye is unable to distinguish a computer photographic image from a real one is 24 bits, i.e. about 16 million colors.
Raster graphics formats for the web
Of course, the size of the graphic file in bytes directly depends on the amount of color information. Therefore, a compromise is necessary between playback quality and graphics file size, which is achieved, in particular, by optimizing graphics. There are 2 main raster graphics formats used on the web – GIF and JPG.
GIF is capable of storing information about any number of colors from 2 to 256; by reducing the number of colors, a sharp reduction in file size is achieved.
In JPG format, the image is simplified by splitting it into rectangular areas of various sizes, filled with one color or a two-color gradient.
Pixel
A raster image is a grid or raster whose cells are called pixels. In other words, you can imagine that an image consists of a finite number of squares of a certain color. These squares are called pixel (from PICture ELement) - pixel or pixel
Each pixel in a raster image has a strictly defined position and color. Any object is interpreted as a set of colored pixels. When processing raster images, it is not specific objects and contours that are edited, but the groups of pixels that make them up. Raster images provide highly accurate color and tonal gradations and are good for displaying photographs. The quality of raster images depends on the resolution of the equipment, since any image consists of a certain number of pixels. Incorrect text processing, such as resizing, can cause drawing borders to become jagged and fine details may be lost.
Size and resolution
The main characteristics of a raster image: size and resolution.
The size of a raster image is specified in pixels. As was said, pixels are conditional squares into which the real image is divided. In this case, the number of pixels in the horizontal and vertical lines is indicated. For example, “raster 2048 by 1536 pixels” means that the image is a matrix of 2048 pixels wide and 1536 high.
The number of pixels per unit length is called image resolution and is measured in pixels per inch ppi (pixels per inch) or dots per inch, and dpi (dots per inch) - for a monitor, printer, scanner. It determines how many pixels a line of length 1 will turn into inch.
An image with a higher resolution contains more pixels that are smaller in size. The resolution largely determines the image quality.
When it comes to input/output devices, typically units from 100 dpi to 2400 dpi are used. 100 dpi is a very mediocre quality, absolutely unsuitable for any professional activity. Laser printers typically have between 300 and 600 dpi
The size of the image on the screen determines the number of pixels in the image, the size of the monitor and its parameters. A large monitor with a 640x480 screen matrix has larger pixels than a small one with the same dimension. The resolution of the PC monitor is 96 dpi. When placing an image, you need to take this into account. For example, an image with 144 ppi on a screen with a resolution of 72 dpi is twice its actual size.
If a scanned image is presented on the monitor, the quality is determined during scanning depending on the set resolution. A subsequent increase in resolution in a graphics editor does not lead to an improvement in the image, since the data is redistributed over a larger number of pixels.
An image consists of a finite number of pixels. Each pixel in the picture has a specific color, indicated by a number.
For example, you can view an image in order from left to right and top to bottom and write down the color numbers of the pixels encountered. You'll get a line something like this:
212= 45= 67= 45= 127= 4= 78= 245= 34 ...
This line is our digitized data. Now we can compress them (since uncompressed graphics data is usually quite large) and save it to a file. In addition, the graphic editor can manipulate this data, realizing all the wildest ideas of your imagination.
Color coding
All pixels have a color, indicated in a certain way by a number. How to determine what number is needed? There are a number of color encoding methods, which are divided into 2 main groups: indexed (with a palette) and full color.
The idea behind indexed rasters is that the color number is actually the number of the "paint" that the pixel is painted with. Therefore, in addition to the pixel colors themselves, the program also needs to know the “palette” from which these colors are selected. This method is similar to the methods of a real artist, but is not very well suited for processing on a computer, since the program, in addition to the pixels themselves, also has to struggle with the palette, selecting the most suitable colors.
The second method is that from the color number we can directly determine the color itself.
Color coding defines Color Depth - the number of bits (bytes) a pixel uses to represent color.
Setting this option determines the following image types.
A black and white image contains only 2 colors - black and white, coded 0 and 1 respectively. The color depth in this case is 1 bit.
The indexed image, unlike the black and white mode, has a richer palette. How much? Determine for you. As a rule, graphic editors support a palette from 2 (not necessarily black and white) to 256 colors. The number of colors in the palette determines two mutually opposite parameters - image quality and its size.
As the quality improves, the size also increases - 9, 13 and 32 KB, respectively. For example, for 6 colors - 3 bits, for 8 - also 3 bits, for 16 - 4 bits and for 256 - 8 bits.
Halftone (grayscale, Grayscale). Here we take black as 0, white as 255, and intermediate shades are indicated by the corresponding numbers. For example - 68 is a color closer to black (dark gray, let's say...). In this case, it is much more convenient to carry out mathematical operations on the image, since its number can be directly determined by color. Color depth - 8 bits.
Full color. As you know, any color can be represented as a mixture of the three main colors - red, blue and green in various proportions. This is what is used when using full-color images. Each channel - R, G or B (Red, Green, Blue - Red, Green or Blue) has its own separate parameter, indicating the amount of the corresponding component in the final color. For example - (255,64, 23) - a color containing a strong red component, a little green and very little blue. Naturally, this mode is most suitable for conveying the richness of the colors of the surrounding nature: But it also requires high costs, since the color depth here is the greatest - 3 channels of 8 bits each give 24 bits.
Raster graphics, general information
A computer raster image is represented as a rectangular matrix, each cell of which is represented by a colored dot.
basis raster graphics representation is pixel(dot) indicating its color. When describing, for example, a red ellipse on a white background, you must indicate the color each ellipse and background points. The image is represented as a large number of dots - the more there are, the visually better the image and the larger the file size. Those. one or even a picture can be presented with better or worse quality in accordance with the number of dots per unit length - resolution(usually dots per inch - dpi or pixels per inch - ppi).
Raster images resemble a sheet of checkered paper, on which each cell is painted either black or white, together forming a pattern. Pixel- the main element of raster images. It is these elements that make up a raster image, i.e. raster graphics describe images using colored dots ( pixels), located on the grid.
When editing raster graphics, you are editing pixels, not lines. Raster graphics are resolution-dependent because information describing the image is attached to a grid of a specific size. When editing raster graphics, the quality of its presentation may change. In particular, resizing raster graphics can cause the edges of the image to become frayed as the pixels are redistributed on the grid. Outputting raster graphics to devices with a lower resolution than the resolution of the image itself will reduce its quality.
In addition, quality is also characterized by the number of colors and shades that each point in the image can take on. The more shades an image is characterized by, the more digits are required to describe them. Red can be color number 001, or it can be color number 00000001. Thus, the higher the quality of the image, the larger the file size.
Raster representation is typically used for photographic-type images with a lot of detail or shading. Unfortunately, scaling such images in any direction usually degrades the quality. When the number of dots is reduced, small details are lost and the inscriptions are deformed (although this may not be so noticeable if the visual size of the image itself is reduced - i.e., the resolution is maintained). Adding pixels leads to a deterioration in the sharpness and brightness of the image, because new points have to be given shades that are average between two or more adjacent colors.
Using raster graphics, you can reflect and convey the entire range of shades and subtle effects inherent in a real image. A raster image is closer to a photograph; it allows you to more accurately reproduce the main characteristics of a photograph: illumination, transparency and depth of field.
Most often, raster images are obtained by scanning photographs and other images, using a digital camera, or by “capturing” a frame from a video. Raster images can also be obtained directly in raster or vector graphics programs by converting vector images.
Common formats .tif, .gif, .jpg, .png, .bmp, .pcx etc.
Raster image representations
Pixel- the main element of raster images. These are the elements that make up a raster image.
Digital image is a collection of pixels. Each pixel of a raster image is characterized by x and y coordinates and brightness V(x,y) (for black and white images). Since pixels are discrete in nature, their coordinates are discrete quantities, usually integers or rational numbers. In the case of a color image, each pixel is characterized by x and y coordinates, and three brightnesses: red brightness, blue brightness and green brightness (VR, V B, V G). By combining these three colors you can get a large number of different shades.
Note that if at least one of the characteristics of the image is not a number, then the image belongs to the form analog . Examples of analogue images include halograms and photographs. To work with such images, there are special methods, in particular, optical transformations. In some cases, analog images are converted to digital form. This task is carried out by Image Processing.
The color of any pixel in a raster image is stored using a combination of bits. The more bits used for this, the more shades of colors can be obtained. 1 byte is usually allocated for brightness gradation (256 gradations), with 0 being black and 255 being white (maximum intensity). In the case of a color image, a byte is allocated for the gradation of brightness of all three colors. It is possible to encode gradations of brightness with a different number of bits (4 or 12), but the human eye is capable of distinguishing only 8 bits of gradations for each color, although special equipment may require more accurate color reproduction. Colors described in 24 bits provide over 16 million available colors and are often called natural colors.
In color palettes, each pixel is described by a code. The connection of this code with a color table consisting of 256 cells is supported. The capacity of each cell is 24 bits. The output of each cell is 8 bits for red, green and blue.
The color space formed by the intensities of red, green and blue is represented as a color cube
The vertices of the cube A, B, C are the maximum intensities of green, blue and red respectively, and the triangle they form is called Pascal's triangle . The perimeter of this triangle corresponds to the most saturated colors. The color of maximum saturation always contains only two components. On the segment OD there are shades of gray, with current O corresponding to black, and point D to white.
Types of rasters
Raster- this is the order of arrangement of points (raster elements). In Fig. 2. a raster is shown, the elements of which are squares, such a raster is called rectangular, these are the rasters that are most often used.
Although it is possible to use a figure of a different shape as a raster element: triangle, hexagon; meeting the following requirements:
- all figures must be the same;
− must completely cover the plane without running over or holes.
So, as a raster element, it is possible to use an equilateral triangle, a regular hexagon (hexahedron). You can build rasters using irregular polygons, but there is no practical meaning in such rasters.
Let's look at ways to construct lines in a rectangular and hexagonal raster.
In a rectangular raster, line construction is carried out in two ways:
1) The result is an eight-connected line. Adjacent pixels on a line can be in one of eight possible positions. The disadvantage is that the line is too thin at an angle of 45°.
2) The result is a four-connected line. Adjacent pixels on a line can be in one of four possible positions. Disadvantage - excessively thick line at an angle of 45°.
In a hexagonal raster, the lines are six-connected (see Fig. 6), such lines are more stable in width, i.e. line width dispersion is less than in a square raster.
One of the ways to evaluate a raster is to transmit over a communication channel a coded image, taking into account the raster used, with subsequent restoration and visual analysis of the achieved quality. It has been experimentally and mathematically proven that the hexagonal raster is better, because provides the smallest deviation from the original. But the difference is not big.
Modeling a hexagonal raster. It is possible to construct a hexagonal raster based on a square one. To do this, a hexagon is represented as a rectangle.
Factors that affect the amount of memory consumed by a bitmap
Raster graphics files take up a large amount of computer memory. Some pictures take up a large amount of memory due to the large number of pixels, each of which takes up some of the memory. Three facts have the greatest impact on the amount of memory occupied by a raster image:
− image size;
− bit color depth;
− file format used to store the image.
There is a direct relationship with the size of the bitmap image file. The more pixels there are in an image, the larger the file size. The image resolution does not affect the file size in any way. Resolution only affects file size when scanning or editing images.
The relationship between bit depth and file size is direct. The more bits used in a pixel, the larger the file will be. The size of a raster graphics file depends greatly on the image format chosen for storage. All other things being equal, such as image size and bit depth, the image compression scheme is essential. For example, a BMP file is usually larger in size compared to PCX and GIF files, which in turn are larger than a JPEG file.
Many image files have their own compression schemes and may also contain additional data to briefly describe the image for preview purposes.
Advantages and disadvantages of raster graphics
Advantages:
Raster graphics effectively represent real-life images. The real world consists of billions of tiny objects, and the human eye is precisely adapted to perceive a huge set of discrete elements that form objects. At their highest level of quality, the images look quite real, similar to how photographs look compared to drawings. This is only true for highly detailed images, usually obtained by scanning photographs. Besides their natural appearance, raster images have other advantages. Output devices such as laser printers use patterns of dots to create images. Raster images can be printed very easily on such printers because it is easy for computers to control the output device to represent individual pixels using dots.
Raster graphics
The smallest unit of raster graphics is the pixel (dot). Raster images resemble a sheet of checkered paper, on which each cell is painted over with some color, collectively forming a pattern (bitmap). The main characteristics of raster graphics are color depth And permission.
Color depth.
Color depth is the number of bits allocated to color encoding.
Depending on how many bits are allocated to the color of each pixel, a different number of colors can be encoded. Thus, color depth allows you to determine the maximum number of colors that can be implemented in an image. For example, if the color depth is 24 bits, then the image can contain up to 16.8 million different colors and shades (i.e. 2 24 ≈ 16.8 million). Obviously, the more colors are used to electronically represent an image, the more accurate the information about the color of each of its points (i.e., its color rendering).
Permission.
Resolution is the number of pixels per unit length, the density of which determines the image quality (display of colors and image details). The most commonly used unit of length is the inch, but sometimes millimeters can be used. Image resolution is measured in dpi (dots per inch).
The higher the image resolution, the better quality it will be, but the larger the file size will be, which must be taken into account when creating and editing images. If the image is intended to be displayed on a monitor screen, then the resolution may be lower than if this image is intended for printing (a resolution of 72 dpi or 96 dpi is usually sufficient for displaying an image on the screen; for printing it, from 150 dpi up to 300 dpi, and in the case of typographic printing it can be much larger).
+ Advantages of raster graphics:
- display of a large number of colors
- display of gradients and color transitions
- display of a large number of small details
- Disadvantages of raster graphics:
- When you make an image smaller, the quality deteriorates because small details are lost
- When you enlarge the image, the quality deteriorates, because the dot size increases (pixelation effect)
- the higher the resolution and color depth, the larger the file size
Raster graphics editors
Raster graphic editors are designed both for processing ready-made images (photos, scanned images) and for creating images. Examples of such editors are Adobe PhotoShop, Corel PhotoPaint, Ulead PhotoImpact GIMP
Images in raster graphics presented as an array of numbers. The main element of the image is the dot. When displayed on a screen, this point is called pixel(from the English expression picture element – pixel). In a digital image, each raster point (pixel) is represented by a single parameter - color. This is what is meant when we consider the concept of "pixel value".
It is necessary to distinguish between technical and mathematical raster. Technical raster– an integer lattice on the plane. For example, this is how an image is realized on a TV screen or monitor. To represent a geometric image, a set of raster elements on an integer plane is used. In what follows we will use only this parameter, and we will call it raster(raster map – bitmap). Upon closer inspection, the image resembles a mosaic panel - you can see the small phosphor dots - the pixels that make up the screen image. Looking at any illustration in books and magazines, you can also notice that the image is built from dots. However, the raster dots are small enough for the human eye to perceive a collection of multi-colored dots as a single picture, and not each of them separately.
For raster graphics, the concept of resolution is key. Permission– the number of points per unit length. There are:
- original resolution;
- monitor resolution;
- print resolution.
Both drawing and sketching have their advantages and disadvantages.
The advantage of drawing programs (raster graphics) is the completely natural way of creating images. If we take the Photoshop program as an example, then, despite all its complexity, the basic visual tools underlying this program are no more complicated than an ordinary pencil. The user alternates drawing and erasing what he has drawn until he achieves what he wants, just as he did in elementary school. Raster images provide maximum realism, since every smallest fragment of the original is translated into digital form.
Despite the simplicity of the basic Photoshop tools, the user can also customize them “to suit themselves.” This equates to an endless variety of crayons, colored pencils, spray bottles, watercolors, oil paints, and more. Moreover, the drawing can be erased, corrected, etc. at any time.
Another advantage seems to be simplicity and, as a consequence, the technical feasibility of automating the input (digitization) of visual information. This simplicity is based on forced sampling into elements and digitizing them in accordance with any predefined quantization tables. There is a developed system of external devices for inputting photographs, slides, drawings, watercolors and other fine originals, these include scanners, video cameras, and digital cameras. These external devices are constantly being improved, providing the ability to increasingly adequately convert images on physical media (paper, film, etc.) into digital form.
Raster graphics have software independence. This advantage, to a certain extent, is also a consequence of the simple principle underlying pixel art. The nature of the information (a collection of numbers organized in a two-dimensional matrix) that is required to store a pixel image allows the creation of standard formats. These formats are “understood” by almost all programs that work with images: pixel and vector graphics editors, layout programs, browsers and even operating systems.
Disadvantage of drawing programs - in limited resolution.Because the bitmap consists of a fixed number of pixels, the resolution of the image depends on the size at which the image is printed. In a small printout, the pixels are small and the resolution is high; Larger printouts enlarge pixels and reduce resolution. An image on a 15-inch screen (800x600 pixels) will only produce a continuous color change in a printout the size of half a postage stamp. If you print it “full-length” on A4 paper, individual pixels will be clearly visible, forming jagged lines in place of smooth lines. The only way to deal with this situation is to increase the number of pixels in the image, which, however, entails a sharp increase in the size of the image file. Since the image consists of dots, enlarging the image only leads to the fact that these dots become larger. It is not possible to see any additional details when enlarging the raster image. The very increase in raster dots visually distorts the illustration and makes it rough. This effect is called pixelation.
Thus, The quality of raster images depends on their size. As a consequence of the fact that they consist of pixels of a fixed size, free scaling without loss of quality is not applicable to them. This feature, as well as the structure of raster images itself, makes their editing and processing somewhat difficult. You can improve image quality by increasing the resolution, but this leads to a significant increase in file size. Therefore, one of the main disadvantages of raster graphics is large file sizes.
V= L W R 2 D
Where, L is the image length in inches, W is the image width in inches, R is the resolution in ppi, D is the color depth.
A serious flaw will surface when trying to rotate an image slightly, such as one with clear thin vertical lines, by a small angle. It is immediately apparent that clear lines turn into “steps”. This means that for any transformations (rotations, scaling, tilting, etc.) in bitmap it is impossible to do without distortion(this is dictated by the discrete nature of the image). You could even say that bitmap graphics are easier to deform than to transform.
When editing bitmaps color changes a certain set of pixels. The change in color results in a change in the shape of the depicted objects.
A serious disadvantage is hardware dependency Raster graphics.
If we take a general look at external devices, almost all of them visualize images using a bitmap. Any image is built from a combination of some elements (for example, screen pixels, ink drops, toner dots), so each of these devices is characterized by its own resolution. And this parameter plays a significant role when printing an image, since a discrete image grid is superimposed on the discrete grid of the device. And this “meeting” is not always favorable for the final result. In particular, it is this “event” that causes moire (moire will be discussed in more detail in the section Printing images).
On the other hand, the image sampling grid is formed, unfortunately, at the very beginning of the process, and subsequent changes to the sampling grid (resolution), as we found out earlier, do not provide any improvement at all.
Computer graphics have quietly but firmly entered our everyday lives. It has long ceased to be the lot of the elite. Every time you transfer photos from a digital camera to a computer or simply click on the “save” button to add a picture you like to your collection, you are working with computer graphics.
Is it worth spending time on theory?
Knowing the basics of how image manipulation works will serve you well. Extensions after the file name will no longer be some kind of magical gobbledygook for you, but will begin to properly supply important information. You can consciously decide which images are best to compress so as not to waste space on your hard drive, and wisely choose which way to do this.
Editing your own photos will also move from the “scientific poking method” to a completely new level. And for some, innocent fun with images on the screen gradually turned into quite profitable work.
Difference between raster and vector graphics
At the moment, vector and raster graphics are mainly used in the computer environment. They differ radically from each other in the way they encode information.
It's no secret that all data on a computer is recorded using binary code. Thus, any information, be it text, picture or sound, is encrypted in a certain way. In order to save a vector image, it is divided into elementary geometric figures, which, in turn, are described by the simplest mathematical formulas. Thus, for example, the letter “and” for a graphic editor will be described by two parallel segments of a given length, which are connected by a line at an angle of 45 degrees.
A raster image is divided according to a different principle. The computer splits the image into many dots, called pixels, and remembers the color and location of each pixel.
Advantages and Disadvantages
If you are working with a vector drawing, you can theoretically enlarge it indefinitely. Moreover, this will in no way affect the quality of the image. Since the parameters are given in the form of geometric formulas, the computer simply processes them and fills all the spaces with the required colors. As a result, you have a clear image.
The disadvantages of raster graphics lie precisely in the fact that during compression (which in the vast majority of cases occurs when saving a file) the quality can significantly suffer. So-called graininess appears. However, it is raster graphics that are used in complex images. In vector drawings you can only create very simple pictures. So for now we'll focus on where raster graphics are used.
Applications
Raster images perfectly convey the content of scanned objects. With their help you can work with halftones and smooth color transitions. Photos taken with a digital camera also use raster images exclusively. This format also serves as an indispensable tool in the field of web design.
Raster graphics formats
Recall that image information in our case is encoded using dots. The unit of measurement in this encoding is the pixel. It is the smallest point that cannot be divided either in size or color.
The number of these points per given unit area is called resolution. In an image with higher resolution (a large number of individual dots), we will see a clear pattern and smooth color transitions. However, in the case when the resolution is small, the quality of the picture can suffer greatly (after all, the computer simply displays the number of pixels available in its memory on the screen and stretches them to the requested size).
It can be roughly compared to language. In order to convey the same information in different languages, different numbers of letters, sounds and words are required. Also, in most cases the grammatical construction will differ. And the “translators” from these “languages” in our computers are specialized programs that either “read” it or convert it into the required format.
The main difference between the formats remains the way information is stored. Let's look at the most common ones.
BMP
This is one of the pioneers. When it was developed, raster graphics were, one might say, at the very origins of their existence. The creators didn’t bother too much and programmed the BMP to memorize each pixel sequentially. In fact, this is just copying, but with some loss of color, since the BMP format only has 256 colors.
TIFF
Quite cumbersome on the scale of digital storage, but simply irreplaceable when outputting information to print. Unlike BMP, it supports information capability. Moreover, for this you can use not one, but several different algorithms. However, unless you work in the printing industry or at least some kind of publishing, you won't really need the serious power of this format.
GIF
This is a format closer to real use (for non-specialists). It is especially famous for its ability to use animation sequences. Computer graphics made in this format also allows you to create translucent images. However, you will not be able to convey smooth color transitions. The most common use of raster graphics in the GIF format can be seen in web design. It is compatible with all platforms and also compresses information quite compactly, which is an important factor in the speed of opening Internet pages.
JPEG
The most popular format. And this is well deserved. Any raster graphics editors undoubtedly support this format. It was designed with the specific goal of getting rid of the limitations imposed by GIF file compression. in this format reaches a coefficient of 100 units. This is a big indicator. However, such compression still has its drawbacks - some data loss occurs, and it is possible that the saved image will become somewhat blurry. Since this format simply discards information it considers unimportant, there is always a risk that some details will be distorted.
JPEG 2000
An improved version of an earlier version. Image information is compressed even more compactly, and there are significantly fewer losses in quality. Most often, this format is used to store photos on a computer’s hard drive and on the Internet. However, keep in mind that if you repeatedly save the same image in JPEG or JPEG 2000 formats, it will lose bits of information each time, and you will end up with an image that is significantly distorted compared to the original.
PNG
A significantly improved quality counterpart to the GIF format. Having retained literally all the advantages of its predecessor, it is devoid of its disadvantages. Used both for and in web page design. In addition, PNG, unlike GIF, is officially freely available.
PSD
Raster graphics in PSD format are processed exclusively in Adobe Photoshop. This is an internal package of this program. It supports working with layers of an edited image.
CDR
It is also an internal package for a raster graphics program. Typically, this program is used by graphic designers to create images from scratch. But the editing function is undoubtedly supported.
Raster graphics editors
And now a little about programs that work with image editing.
The most popular program among users at the moment is the Adobe Photoshop program, commonly referred to simply as “Photoshop”. This development, in fact, monopolized the work with raster images among design specialists. However, this program is paid and it does not cost that little. Therefore, developments from other companies began to appear. Some of them have already been widely used.
As for Photoshop itself, this did not affect its popularity in any way. The program is quite simple, and there is no shortage of various video courses and tutorials.
In Photoshop, you can not only make a collage of photos or add built-in effects to the image. The simplest functions of this program can be mastered very quickly, and this will open the door to unbridled flights of imagination. You can correct defects in appearance, adjust the color scheme, change the background and much, much more.
Graphics editor GIMP
As for free programs, we can safely recommend GIMP. This graphic editor can easily supplant the popular Photoshop. It excels at all the tasks needed for raster image editing and has some introductory features for working with vector graphics.
The GIMP program allows you to make photos more rich and vibrant, it easily removes unnecessary elements from the image and can be used for preparing professional design projects. Computer graphics created with this program look natural and fit seamlessly into the overall picture.
Graphics editor Corel DRAW
It would be wrong to ignore Corel products. In Corel DRAW, you can easily work with both raster and vector images. The capabilities of this tool are so numerous that studying the Corel DRAW program is included in the mandatory training course for graphic designers in colleges.
This program is also paid, and the arsenal of its products is replenished with enviable regularity. But, despite the wide range of possibilities that this graphic editor provides the user, its intuitive interface makes the work process a pleasure.
Free graphic editors
And just a few more words about alternative image editing programs. In most cases, they cope well with the needs of the average user, and take up much less space and resources on your computer. And it’s generally easier to work with them, since you won’t be overloaded with the need to choose among all sorts of functions, the purpose of which remains unclear.
If you like unusual and mostly humorous photographs, try using the Funny Photo Maker program. There you will find many original frames and fun visual effects.
For more serious work, Picasa is suitable. This editor is designed for use in computer networks. Its new features will make it even easier for you to design your pages on social networks. And the built-in effects for editing will not disappoint even a seasoned specialist.
Another interesting program is Paint.NET. It is very similar in its functions and capabilities to Adobe Photoshop. And the tools used in Paint.NET can seriously compete with the mentioned commercial analogue.
