Last Chaos on mäng kus pead valima enda mehe ja temaga seiklusele asuma kus pead tapma koletisis 6 erinevas maailmas, tegema missioone ja aitama inimesi, kasvatama loomi ja mud sellist saad uuendada oma relvi ja armorit ning ka tugevust ja special asju soovitan seda inimesele kellel on igav ja palju aega

20.01

Ico file format

The ICO file format is an image file format for computer icons in Microsoft Windows. ICO files contain one or more small images at multiple sizes and color depths, such that they may be scaled appropriately. In Windows, all executables that display an icon to the user, on the desktop, in the Start Menu, or in Windows Explorer, must carry the icon in ICO format.

The CUR file format is an almost identical image file format for non-animated cursors in Microsoft Windows. The only differences between these two file formats are the bytes used to identify them and the addition of a hotspot in the CUR format header; the hotspot is defined as the pixel offset (in x,y coordinates) from the top-left corner of the cursor image where the user is actually pointing the mouse.

requirements If you have an Windows icon editor (which you may already have if you have purchased a programming language development system for Windows), you're all set.

Pixel 

16x16 ja 32x32

vastused 14

 

Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail.

Image resolution can be measured in various ways. Basically, resolution quantifies how close lines can be to each other and still be visibly resolved. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtenant. Line pairs are often used instead of lines; a line pair comprises a dark line and an adjacent light line. A line is either a dark line or a light line. A resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm).Photographic lens and film resolution are most often quoted in line pairs per millimeter.

Contents [hide] 1 Resolution of digital images 1.1 Pixel resolution 1.2 Spatial resolution 1.3 Spectral resolution 1.4 Temporal resolution 1.5 Radiometric resolution 2 Resolution in various media 3 See also 4 References 5 External links

[edit]Resolution of digital images

The resolution of digital images can be described in many different ways.

[edit]Pixel resolution

The term resolution is often used for a pixel count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field.^[1][2] An image of N pixels high by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as resolution, the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 640 by 480. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions, but they are widely referred to as such; they serve as upper bounds on image resolution.

According to the same standards, the number of effective pixels that an image sensor or digital camera has is the count of elementary pixel sensors that contribute to the final image, as opposed to the number oftotal pixels, which includes unused or light-shielded pixels around the edges.

Below is an illustration of how the same image might appear at different pixel resolutions, if the pixels were poorly rendered as sharp squares (normally, a smooth image reconstruction from pixels would be preferred, but for illustration of pixels, the sharp squares make the point better).

An image that is 2048 pixels in width and 1536 pixels in height has a total of 2048×1536 = 3,145,728 pixels or 3.1 megapixels. One could refer to it as 2048 by 1536 or a 3.1-megapixel image.

Unfortunately, the count of pixels isn't a real measure of the resolution of digital camera images, because color image sensors are typically set up to alternate color filter types over the light sensitive individual pixel sensors. Digital images ultimately require a red, green, and blue value for each pixel to be displayed or printed, but one individual pixel in the image sensor will only supply one of those three pieces of information. The image has to be interpolated or demosaiced to produce all three colors for each output pixel.

[edit]Spatial resolution

The 1951 USAF resolution test target is a classic test target used to determine spatial resolution of imaging sensors and imaging systems.

Image at left has a higher pixel count than the one to the right, but is still of worse spatial resolution.

The measure of how closely lines can be resolved in an image is called spatial resolution, and it depends on properties of the system creating the image, not just the pixel resolution in pixels per inch (ppi). For practical purposes the clarity of the image is decided by its spatial resolution, not the number of pixels in an image. In effect, spatial resolution refers to the number of independent pixel values per unit length.

The spatial resolution of computer monitors is generally 72 to 100 lines per inch, corresponding to pixel resolutions of 72 to 100 ppi. With scanners, optical resolutionis sometimes used to distinguish spatial resolution from the number of pixels per inch.

In geographic information systems (GISs), spatial resolution is measured by the ground sample distance (GSD) of an image, the pixel spacing on the Earth's surface.

In astronomy one often measures spatial resolution in data points per arcsecond subtended at the point of observation, since the physical distance between objects in the image depends on their distance away and this varies widely with the object of interest. On the other hand, in electron microscopy, line or fringe resolution refers to the minimum separation detectable between adjacent parallel lines (e.g. between planes of atoms), while point resolution instead refers to the minimum separation between adjacent points that can be both detected and interpreted e.g. as adjacent columns of atoms, for instance. The former often helps one detect periodicity in specimens, while the latter (although more difficult to achieve) is key to visualizing how individual atoms interact.

In Stereoscopic 3D images, spatial resolution could be defined as the spatial information recorded or captured by two viewpoints of a stereo camera (left and right camera). The effects of spatial resolution on overall perceived resolution of an image on a person's mind are yet not fully documented. It could be argued that such "spatial resolution" could add an image that then would not depend solely on pixel count or Dots per inch alone, when classifying and interpreting overall resolution of a given photographic image or video frame.

[edit]Spectral resolution

Color images distinguish light of different spectra. Multi-spectral images resolve even finer differences of spectrum or wavelength than is needed to reproduce color. That is, they can have higher spectral resolution. that is the strength of each band that is created ( Lihongeni mulama: 2008)

[edit]Temporal resolution

Movie cameras and high-speed cameras can resolve events at different points in time. The time resolution used for movies is usually 15 to 30 frames per second (frames/s), while high-speed cameras may resolve 100 to 1000 frames/s, or even more.

Many cameras and displays offset the color components relative to each other or mix up temporal with spatial resolution:

• 

  digital camera (Bayer color filter array)
• 

  LCD (Triangular pixel geometry)
• 

  CRT (shadow mask)

[edit]Radiometric resolution

Main article: Color depth

Radiometric resolution determines how finely a system can represent or distinguish differences of intensity, and is usually expressed as a number of levels or a number of bits, for example 8 bits or 256 levels that is typical of computer image files. The higher the radiometric resolution, the better subtle differences of intensity or reflectivity can be represented, at least in theory. In practice, the effective radiometric resolution is typically limited by the noise level, rather than by the number of bits of representation.

[edit]Resolution in various media

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2008)

This is a list of traditional, analog horizontal resolutions for various media. The list only includes popular formats, not rare formats, and all values are approximate (rounded to the nearest 10), since the actual quality can vary machine-to-machine or tape-to-tape. For ease-of-comparison, all values are for the NTSC system. (For PAL systems, replace 480 with 576.)

• Analog and early digital
  • 352×240 : Video CD
  • 300×480 : Umatic, Betamax, VHS, Video8
  • 350×480 : Super Betamax, Betacam (pro)
  • 420×480 : LaserDisc, Super VHS, Hi8
  • 640×480 : Analog broadcast
  • 670×480 : Enhanced Definition Betamax
  • 768×576 : Analog broadcast (PAL)

• Digital
  • 720×480 : D-VHS, DVD, miniDV, Digital8, Digital Betacam (pro)
  • 720×480 : Widescreen DVD (anamorphic)
  • 1280×720 : D-VHS, HD DVD, Blu-ray, HDV (miniDV)
  • 1440×1080 : HDV (miniDV)
  • 1920×1080 : HDV (miniDV), AVCHD, HD DVD, Blu-ray, HDCAM SR (pro)
  • 2048×1080 : 2K Digital Cinema
  • 4096×2160 : 4K Digital Cinema
  • 7680×4320 : UHDTV
  • Sequences from newer films are scanned at 2,000, 4,000, or even 8,000 columns, called 2K, 4K, and 8K, for quality visual-effects editing on computers.

• Film
  • 35 mm film is scanned for release on DVD at 1080 or 2000 lines as of 2005.
  • The actual resolution of 35 mm camera original negatives is the subject of much debate. Measured resolutions of negative film have ranged from 25-200 lp/mm, which equates to a range of 325 lines for 2-perf, to (theoretically) over 2300 lines for 4-perf shot on T-Max 100.^[3][4][5] Archivists generally agree that 4k scanning of 35mm is more than adequate for archival purposes.^[6]. However some photography sources gives 5380 x 3620 as the resolution of 35mm film.^[7]. It is similar to 19.5 Mpix, of course with identical spatial resolution ^[8].
  • IMAX, including IMAX HD and OMNIMAX: approximately 10,000×7000 (7000 lines) resolution. It is about 70 Mpix^[9], which may be compared to the biggest resolution, single sensor digital cameras(as of January 2012) - 80 Mpix ^[10]

In computer graphics, color depth or bit depth is the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel (bpp), particularly when specified along with the number of bits used. Higher color depth gives a broader range of distinct colors.

Color depth is only one aspect of color representation, expressing how finely levels of color can be expressed; the other aspect is how broad a range of colors can be expressed (thegamut).

Contents [hide] 1 Indexed color 2 Direct color 2.1 8-bit color 2.2 16-bit color 2.2.1 LCD displays 2.3 Truecolor 2.4 Deep color 2.5 Industry support 2.5.1 Television color 3 See also 4 References 5 External links

[edit]Indexed color

Main article: Indexed color

With relatively low color depth, the stored value is typically a number representing the index into a color map or palette. The colors available in the palette itself may be fixed by the hardware or modifiable within the limits of the hardware (for instance, both color Macintosh systems and VGA-equipped IBM-PCs typically ran at 8-bit due to limited VRAM, but while the best VGA systems only offered an 18-bit (262,144 color) palette from which colors could be chosen, all color Macintosh video hardware offered a 24-bit (16 million color) palette). Modifiable palettes are sometimes referred to as pseudocolor palettes.

1 bit (2 colors)

• 1-bit color (2¹ = 2 colors) monochrome, often black and white, compact Macintoshes, Atari ST.
• 2-bit color (2² = 4 colors) CGA, gray-scale early NeXTstation, color Macintoshes, Atari ST.

2 bits (4 colors)

• 3-bit color (2³ = 8 colors) many early home computers with TV displays

4 bits (16 colors)

• 4-bit color (2⁴ = 16 colors) as used by EGA and by the least common denominator VGA standard at higher resolution, color Macintoshes, Atari ST.
• 5-bit color (2⁵ = 32 colors) Original Amiga chipset
• 6-bit color (2⁶ = 64 colors) Original Amiga chipset

8 bits (256 colors)

• 8-bit color (2⁸ = 256 colors) most early color Unix workstations, VGA at low resolution, Super VGA, color Macintoshes, Atari TT, AGA, Falcon030.
• 12-bit color (2¹² = 4096 colors) some Silicon Graphics systems, Neo Geo, Color NeXTstation systems, and Amiga systems in HAM mode.
• 16-bit color (2¹⁶ = 65536 colors) some color Macintoshes.

Old graphics chips, particularly those used in home computers and video game consoles, often feature an additional level of palette mapping in order to increase the maximum number of simultaneously displayed colors. For example, in the ZX Spectrum, the picture is stored in a two-color format, but these two colors can be separately defined for each rectangular block of 8x8 pixels.

[edit]Direct color

As the number of bits increases, the number of possible colors becomes impractically large for a color map. So in higher color depths, the color value typically directly encodes relative brightnesses of red, green, and blue to specify a color in the RGB color model.

A typical computer monitor and video card may offer 8 bits of resolution (256 output levels) per R/G/B color channel, for an overall 24-bit color space (or 32-bit space, with alpha transparency bits, which have no bearing on the output resolution), though earlier standards offered 6 bits per channel (64 levels) or less; the DVD standard defines up to 10 bits of resolution (1024 levels) for each of the Y/U/V video encoding channels (luminance plus two chrominance channels).

[edit]8-bit color

A very limited but true direct color system, there are 3 bits (8 possible levels) for each of the R and G components, and the two remaining bits in the byte pixel to the B component (four levels), enabling 256 (8 × 8 × 4) different colors. The normal human eye is less sensitive to the blue component than to the red or green,^{[citation needed]} so it is assigned one bit less than the others. Used, amongst others, in the MSX2 system series of computers in the early to mid 1990s.

Do not confuse with an indexed color depth of 8bpp (although it can be simulated in such systems by selecting the adequate table).

[edit]16-bit color

In 16-bit direct color, there can be 4 bits (16 possible levels) for each of the R, G, and B components, plus optionally 4 bits for alpha (transparency), enabling 4,096 (16 × 16 × 16) different colors with 16 levels of transparency. Or in some systems there can be 5 bits per color component and 1 bit of alpha (32768 colors, just fully transparent or not); or there can be 5 bits for red, 6 bits for green, and 5 bits for blue, for 65536 colors with no transparency.^[1] These color depths are sometimes used in small devices with a color display, such as mobile telephones.

Variants with 5 or more bits per color component are sometimes called high color,^[2] which is sometimes considered sufficient to display photographic images.^[3]

[edit]LCD displays

Almost all cheap LCD displays (such as typical twisted nematic types) use dithered 18-bit color (64 × 64 × 64 = 262,144 combinations) to achieve faster transition times, but they must use either dithering or Frame Rate Control to fake 24-bit-per-pixel truecolor, or throw away 6 bits of color information away entirely. The best LCD displays can display 24-bit or greater color depth.

[edit]Truecolor

24 bits (16,777,216 colors, "truecolor")

Truecolor is a method of representing and storing graphical image information (especially in computer processing) in an RGB color space such that a very large number of colors, shades, and hues can be displayed in an image, such as in high quality photographic images or complex graphics. Usually, truecolor is defined to mean at least 256 shades of red, green, and blue, for a total of at least 16,777,216 color variations. The human eye is popularly believed to be capable of discriminating among as many as ten million colors.^[4] Truecolor can also refer to an RGB display mode that does not need a color look-up table (CLUT).^[5]

For each pixel, generally one byte is used for each channel while the fourth byte (if present) is being used either as an alpha channel data or simply ignored. Byte order is usually either RGB or BGR. Some systems exist with more than 8 bits per channel, and these are often also referred to as truecolor (for example a 48-bit truecolor scanner).

Even with truecolor, monochromatic images, which are restricted to 256 levels, owing to their single channel, can sometimes still reveal visible bandingartifacts.

Truecolor, like other RGB color models, cannot express colors outside of the gamut of its RGB color space (generally sRGB).

On Macintosh systems, 24-bit color is referred to as "millions of colors."

[edit]Deep color

Deep color is a term used to describe a gamut comprising a billion or more colors.^[6] The xvYCC, sRGB, and YCbCr color spaces can be used with deep color systems.^[7]

Video cards with 10 bits per color, or 30-bit color, started coming into the market in the late 1990s. An early example was the Radius ThunderPower card for the Macintosh, which included extensions for QuickDraw and Adobe Photoshop plugins to support editing 30-bit images.^[8]

Systems using more than 24 bits in a 32-bit pixel for actual color data exist, but most of them opt for a 30-bit implementation with two bits of padding so that they can have an even 10 bits of color for each channel, similar to many HiColor systems.

While some high-end graphics workstation systems and the accessories marketed toward use with such systems, as from SGI, have always used more than 8 bits per channel, such as 12 or 16 (36-bit or 48-bit color), such color depths have only worked their way into the general market more recently.

As bit depths climb above 8 bits per channel, some systems use the extra bits to store more intensity range than can be displayed all at once, as in high dynamic range imaging (HDRI). Floating point numbers are used to describe numbers in excess of 'full' white and black. This allows an image to accurately describe the intensity of the sun and deep shadows in the same color space for less distortion after intensive editing. Various models describe these ranges, many employing 32-bit accuracy per channel. A new format is the ILM "half" using 16-bit floating point numbers, it appears this is a much better use of 16 bits than using 16-bit integers and is likely to replace it entirely as hardware becomes fast enough to support it.^{[citation needed]}

Many modern desktop systems (Mac OS X, GNOME, KDE, Windows XP/Vista/7, etc.) offer a 32-bit color option (given a suitably modern video card), but in that context, 32-bit color refers to 24-bit truecolor with 8 bits for an alpha channel. When switching to an 8/16/24-bit color option in those systems, generally transparency/translucency effects are disabled, and the only reduction in color depth is seen when going to 8/16-bit color.

[edit]Industry support

The HDMI 1.3 specification defines bit depths of 30 bits (1.073 billion colors), 36 bits (68.71 billion colors), and 48 bits (281.5 trillion colors).^[7] In that regard, the NVIDIA Quadro graphics cards support 30-bit deep color^[9] as do some models of the Radeon 5800 series such as the HD 5970.^[10][11] The ATI FireGL V7350 graphics card supports 40-bit and 64-bit color.^[12]

The DisplayPort specification also supports color depths greater than 24 bpp.

At WinHEC 2008, Microsoft announced that color depths of 30 bits and 48 bits would be supported in Windows 7, along with the wide color gamut scRGB (which can be converted to xvYCC output).^[13][14]

[edit]Television color

Virtually all television displays and computer displays form images by varying the strength (technically, tristimulus values) of just three primary colors: red, green, and blue. Bright yellow, for example, is formed by roughly equal red and green contributions, with little or no blue contribution. Recent technologies such as Texas Instruments's BrilliantColor augment the typical red, green, and blue channels with up to three other primaries: cyan, magenta and yellow.^[15] Mitsubishi and Samsung, among others, use this technology in some TV sets. However, the associated signal processing typically fails to mimic additive mixing; hence, the displayed colors are distorted (for example, compared to sRGB source values). The Sharp Aquos line of televisions has introduced Quattron technology, which augments the usual RGB pixel components with a yellow subpixel. Again, signal processing fails in general to follow the laws of additive mixing, and colors are distorted.

Analog TVs use continuous signals which have no fixed number of different colors, although subject to noise introduced in transmission.

Arvutigraafikas võib välja tuua kaks põhimõtteliselt erinevat süsteemi: rastergraafika ja vektorgraafika.

Rastergraafika

Rastergraafikas (inglise keeles raster graphics või vahel ka pixel graphics) koosneb pilt üksikutest punktidest ehk pikselitest, milledest igaüks omab oma värvi ja on eraldi töödeldav. Rastergraafikat kasutatakse digitaliseeritud fotode ja realistlike joonistuste puhul, kuna saab kasutada väga sujuvaid värviüleminekuid ning objektidel ei pea olema selgeid piirjooni.

Rastergraafika programmid on näiteks Gimp, Paint, Adobe Photoshop ja Corel Photo-Paint.

Rastergraafikat kasutatakse: skaneerimisel, pilditöötluses, graafika loomiseks jne.

Rastergraafika failid on tavaliselt suuremahulised ja nõuavad seetõttu arvutilt palju resursse (palju operatiivmälu, suur kõvaketas, hea videokaart ja kvaliteetne monitor).

Rastergraafika piltidel on mitu olulist parameetrit:

· resolutsioon ehk punktitihedus (eraldusvõime), mida mõõdetakse pikselite arvuga tolli kohta, tähis dpi (dots per inch), levinumad suurused on 75; 100; 150; 200; 300; 400; 600 ja 1200 dpi;

· suurus pikselite arvuna (pildi suurus ekraanipikselites). Mõõt esitatakse küljepikkuste korrutisena järgmiselt: laius x kõrgus (näiteks 600x800);

· värviresolutsioon ehk värvigamma (värvisügavus) näitab, mitu bitti graafikamälu on vaja ühe piksli värvi kirjeldamiseks.

Mida suurem on pildi värvisügavus, seda kvaliteetsem on pilt, kuid selleks on vaja ka paremat graafikakaarti ja monitori ning loomulikult on seda suurem pildifail. Kasutatakse järgmisi värvisügavuse standardeid:

1 bitine värvigamma	2 värvi (must ja valge)
2 bitine värvigamma	4 värvi (must, valge ja kaks halli)
4 bitine värvigamma	16 värvi või halltooni
8 bitine värvigamma	256 värvi
16 bitine värvigamma	65 536 värvi
24 bitine värvigamma	16 777 216 värvi (true color)

Võrdluseks: inimsilm eristab umbes 10 miljonit värvivarjundit.

Rastergraafika iga kujutise pind, ka täiesti valge leht, on ikkagi kaetud selle kujutise mõõtmele ja eraldusvõimele vastava arvu pikselitega. Mistahes rastergraafika kujutisega tegelemine tähendab tegelikult selle kujutise pinnal asuvate pikselite värvuse muutmist. Seega rastergraafika faili maht ei sõltu sellest, mis on pildil kujutatud ja kas ta on must, valge või värviline vaid sõltub eelpool toodud parameetritest: resolutsioonist, pildipinna mõõtmetest, värvisügavusest ning lisaks pildi salvestamisel kasutatavast formaadist ja rakendatavast kompressiooniastmest st meetodist, kuidas on pilt pakitud

Soovitusi rastergraafika töötlemiseks

Rastergraafika pildid on arvutiekraanil alati pisut sakilised, kuna ekraani resolutsioon pole kuigi suur. Peamised puudused töös rastergraafika piltidega tulevad välja siis, kui tegeletakse skaleerimise (scaling ehk suurendamine/vähendamine) ja pööramisega (rotation). Ideaalne on, kui rastergraafika elemendid on loodud selles suuruses, millega neid kasutada soovitakse.

Kui rastergraafika pilti suurendada näiteks 200%, siis keskmine programm asendab iga pikseli kahe pikseliga, mis muudab pildi palju sakilisemaks. Vastupidisel juhul, kui pilti vähendada 50%, siis tuleb osa pikseleid ära kaotada (kõrvuti olevad pikselid liidetakse üheks).

Järgmisel lehel on keskel näha originaalsuuruses rastergraafika pilt, resolutsiooniga 70 dpi, millest kahel pool on skaleeritud koopiad, paremal 50% ja vasakul 200%.

Vähendamisel on parimad skaleerimisvariandid need, mis saadakse 100% jagamisel paarisarvuga, näiteks 50% ja 25%, millede korral "visatakse ära" iga teine või iga neljas piksel. Valides 77% anname me arvutile ülesande, mis toob kindlasti kaasa tehislikkuse probleemi (kujutise loomulikkus kaob).Suurendamisel saab tekkivaid sakilisi ääri ise käsitsi kohendada lisades ja kustutades sobivates kohtades vajalikke pikseleid. On olemas ka programme, mis kasutavad skaleerimisel keerukamat interpolatsioonimeetodit, mis annab juba tunduvalt siledama tulemuse.

Enamus rastergraafikat töötlevaid programme lubavad jooni ja teisi geomeetrilisi kujundeid joonistada ja pöörata mistahes nurga all. Probleem on selles, et kujundite servad, mis on ilusad horisontaal- ning vertikaalsuunas, muutuvad praktiliselt igasuguse nurga all sakiliseks.

Kui Teil on tarvis rastergraafika pildil vähendada nii resolutsiooni kui ka värvigammat, siis sooritage alati enne resolutsiooni muutmine ning alles seejärel värvigamma muutmine. Põhjendus seisneb selles, et resolutsiooni vähendamisega (aga ka pildi väiksemaks skaleerimisel) läheb osa pikseleid kaduma ning sellega tavaliselt kaob ka mingisugune osa värve. Kui alles nüüd värvigammat vähendada, jääb meil lõppkokkuvõttes rohkem erinevaid värve järele ning kujutis loomulikum. Samasugune põhimõte kehtib ka pildist mingi osa väljalõikamisel (crop): enne lõige, siis värvigamma muutus.

Vektorgraafika

Vektorgraafika (vector graphic) ehk objekt-orienteeritud graafika on graafiliste objektide, nagu jooned, kaared, ringid ja ristkülikud, esitlusviis matemaatiliste valemite abil (näiteks ringi loomiseks on vaja teada tema keskpunkti koordinaate, raadiust ja värvi). Objektide selline kirjeldamine võimaldab nendega vabamalt manipuleerida. Näiteks saab objekte üksteise peale asetada ja ikkagi neid eraldi muuta (rastergraafika puhul võib selline ülesanne väga raskeks osutuda). Vektorgraafikaga loodud kujutiste kuvamine või väljatrükk tuleb kvaliteetsem kui rastergraafika korral. Mida suurem on kuvari või printeri lahutusvõime, seda teravam paistab taoline kujutis.

Vektorgraafika programmid on näiteks Adobe Illustrator, Corel Draw, Freehand ja Open Office’i alla kuuluv Draw.

Vektorgraafikat kasutatakse:

• joongraafikast koosnevate plakatite ja muu kõrge kontrastsusega graafika loomiseks;
• arhidektuuriliste plaanide, masinaehitusjooniste, projektide ja jooniste, põhiliselt just joontest koosneva graafika koostamiseks;
• äriinformatsiooni - graafikud, diagrammid, jm andmebaase graafiliselt illustreeriva materjali loomiseks;
• trükiste jm trükitava dokumentatsiooni loomiseks, mis sisaldavad nii teksti kui ka raster- või vektorgraafika kujutisi.

Vektorgraafika eelised:

• vektorgraafika kasutab vähem mälu,
• vektorgraafika trükkimine toimub kiiremini,
• vektorgraafika suuruse muutmisel ja teisaldamisel ei ole piiranguid.

Vektorgraafika puuduseks on see, et suhteliselt raske on luua realistlikku kujutist. Mida realistlikumat kujutist soovitakse luua, seda rohkem objekte selleks vajatakse. Sellepärast ei saa vektorgraafikat kasutada fotode kodeerimiseks. Kui seda aga üritada, on lõppresultaadi maht suurem kui pikselgraafikas sama pildi kodeerimine.

Levinumad pildifaili formaadid

BMP (Bitmap) failiformaadist on saanud Microsoft Windowsis kasutatav standard failiformaat. Esmakordselt ilmus see koos Windows 3.0-ga ja seda toetavad kõik Windowsi programmid (seejuures mõni programm ainult seda tunnistabki).

Enamus Windowsi BMP faile ei kasuta pakkimist ja seetõttu on saadav fail väga suure mahuga. On oluline rõhutada, et internetti ei tasu kunagi panna üles selles formaadis olevaid faile, sest nende allalaadimiseks kulub liiga palju aega, kuna failid on suured. Eriti annab see end tunda aeglaste modemite kasutamise korral.

BMP failid võivad kasutada 1- 24 bitist värvigammat.

BMP faile on võimalik salvestada 16 ja 256 värvitooni kasutava graafika puhul ka pakitud kujule. Selleks on olemas Windowsi RLE (Run-Length Encoded) formaat. RLE formaadi peamisteks kasutusaladeks on pakitud taustade või Windowsi käivitamisel kuvatava logo tegemine. Samas ei ole kõik programmid võimelised pakitud BMP faile avama (näiteks Windowsi Paintbrush).

BMP formaadis oleva faili laiendiks on .bmp, mõnikord ka .dib.

JPEG (Joint Photographic Experts Group) formaadi näol on tegemist nn. pildi kadudega pakkimisega, mis tähendab seda, et mingi osa andmetest läheb töötluse käigus kaduma.

JPEG pakkimise idee seisneb selles, et teatud maalt ei ole inimsilm enam võimeline eristama värvitoonide vahesid. Nii on võimalik vähendada kasutatava värvipaleti suurust (st vähendada erinevaid kasutatavaid värvitoone), kattes omavahel küllalt sarnased toonid ühesuguse tooniga. Tulemuseks saame palju väiksema faili.

Võib arvestada, et parema pakkimistulemuse saadakse piltide puhul, millel on vähe elemente ja vähe erinevaid värve. Kui pilt on väga kirju, sisaldades väga palju väikseid elemente, ei ole pakkimistulemus nii hea ning võib märgata mõningat pildikvaliteedi langust.

JPEG faili loomisel on tavaliselt võimalik valida, kui hea kvaliteediga pilti Te soovite tulemuseks saada (mida kõrgem kvaliteet, sada mahukam fail ja seda pikem allalaadimisaeg ning vastupidi). Kvaliteeti saab kasutaja määrata skaalal, mis kuvatakse tavaliselt salvestusdialoogis.

Pakkimise parameetriteks on skaalad 7:1 kuni 50:1 ning see on sümmeetriline, mis tähendab, et pakkimiseks ja lahti pakkimiseks kulub sama arv operatsioone ja selletõttu ka sama palju aega.

JPEG-formaati võiks teatud mõttes nimetada lõppformaadiks, kuna selles formaadis olevaid pilte töödelda ei tasu, sest igal salvestusel toimub kadudega pakkimine. Kui Te soovite pilti töödelda, tehke seda mingis muus formaadis ning kui kõik on valmis, alles siis salvestage töö JPEG formaati.

JPEG formaadis pilte saab salvestada nii, et neid kuvatakse järk-järgult, järjest paraneva kvaliteediga (udune eelvaate pilt saabub kasutajale peaaegu koheselt).

JPEG faili laiendiks on .jpg.

GIF (Graphics Interchange Format) on patenteeritud pakkimisformaat (omanikeks CompuServe ja Unisys).

GIF kasutab nn kadudeta pakkimist, mis tähendab, et pildi salvestamisel ei kaotata mingeid andmeid. GIF pakkimise idee seisneb selles, et pakkimisel kasutatakse sama tooni alade kirjeldamiseks spetsiaalset kompaktset koodi, mistõttu faili suurus väheneb tunduvalt.

Teine oluline asi GIF formaadi juures on, et kasutatakse kuni 256st värvist koosnevat värvipaletti (värvipalett kajastab kõiki pildil kasutatud värvitoone). Ülejäänud toonid kaotatakse ära.

Osad pilditöötlusprogrammid võimaldavad kasutada pilditöötlusel sellist abivahendit nagu ‘dithering’, mis lubab kasutajal määrata, millist värvitooni tuleb hoida suurima visuaalse kvaliteediga. Samas teeb see faili suuremaks (mida vähem on värve paletis, seda väiksema pildifaili me saame).

Faili salvestamisel GIF formaati on võimalik valida omadus ‘Interlace’, mis tähendab, et pilt laetakse brauseriaknasse kohe, aga algul udusena ning sedamööda kuidas info kohale jõuab, see järjest selgineb.

GIF formaadis pildil võib olla läbipaistvaid piirkordi (omadus ‘Transparent’) (näiteks pildi taust) ning mitmeid erinevaid kihte, mida käsitletakse kaadritena ning mis paistavad läbi läbipaistvatest aladest.

Kui soovite luua animatsioone, tuleb samuti otsustada selle formaadi kasuks.

GIF formaadis faili laiendiks on .gif.

PNG (Portable Network Graphics) on GIF formaadi edasiarendus ja kuna ta on tasuta (patendivaba), siis oodatakse selle formaadi tulevikult palju.

PNG salvestamisel kasutatakse kadudeta pakkimismeetodit.

Sarnaselt GIF formaadile võib ka PNG formaadis pilt olla läbipaistvate osadega. Kuid erinevalt GIFist, kus värv saab olla kas 100% läbipaistev või 100% läbipaistmatu, ilma vahepealsete võimalusteta, pakub PNG võimalust iga värvitooni puhul eraldi määrata läbipaistvuse astme (0-255). See võimaldab luua rohkem ja vähem läbipaistvate aladega pilte. PNG formaat toetab kuni 48 bitist värvisügavust.

PNG ei võimalda luua animatsioone (animeeritud pilte). Soovijad saavad selleks otstarbeks kasutada MNG (Multiple-imageNetworkGraphics) formaati.

TIFF (Tagged Image File Format) formaat töötati välja Microsofti ja Aldus Corporationi poolt kui sobiv meetod bitmap failide hoidmiseks. Formaati toetavad enamus graafikaprogramme.

TIFF formaadis failid võivad olla nii pakitud (kadudeta pakkimine) kui pakkimata kujul. Pakitud formaat annab päris hea tulemuse faili mahu väiksemaks muutmisel, samas ei pruugi kõik, eriti vanemad, graafikaprogrammid suuta pakitud TIFFidega tööd teha (kasutavad TIFF formaadi vanemaid versioone).

TIFF formaadis olevate failide laiendiks on .tif .

TIFF failid võivad olla monokroomses, 16 värvi, 256 värvi, 16 hallskaala tooni, 256 hallskaala tooni või 24-bitises true color süsteemis.

Universaalsed formaadid lubavad salvestada nii raster kui vektorgraafikat. Tuntumateks on PS, EPS, ja PDF. Universaalsetes formaatides salvestatud faile on võimalik avada enamikes graafikaprogrammides.

Värvisüsteem

Värvisüsteem (värvimudel) on süsteem, mille abil saab väikesest arvust algvärvidest luua ülejäänud värvid. On kaks tuntumat värvisüsteemi:

RGB on aditiivne värvisüsteem. Kujutis tekib punase, rohelise ja sinise valguse segamisel (liitmisel).

Põhivärvused on:

· R – Red (punane)

· G – Green (roheline)

· B – Blue (sinine)

Näited kasutusaladest: televiisori ekraan, arvuti monitor; ka skännerid kasutavad RGB värvimudelit.

Kui liita kokku põhivärvid punane, roheline ja sinine, on tulemuseks valge värv. Kui valgust üldse ei ole, on tulemuseks must värv.

CMY(K) on subtraktiivne värvisüsteem. Sobiv värvus tekib erinevate värvikoguste segamisega valgel paberil. Need värvid peegeldavad teatud värvusi ja absorbeerivad teisi. CMY(K) värvimudelit kasutatakse trükitööstuses ja värviprinterites.

Põhivärvused on:

• C – Cyan (sinine, tsüaan)
• M – Magenta (teatavat tooni punane - magenta, fuksia)
• Y -Yellow (kollane)

Selle värvisüsteemi korral peaks teoreetiliselt saama põhivärvide koostoimel musta värv. Praktikas sõltub saadava musta värvi kvaliteet kasutavatest trükivärvidest ja trükkimise protsessist ning tegelikult annavad need kolm värvi tulemuseks tooni, mida inglise keeles nimetatakse muddy brown ehk siis mudane pruun. Seega värvisüsteemi täiustamiseks lisatakse neljandaks värviks must (black), mida nimetatakse antud süsteemi võtmevärviks (key). Selle sõna esitähest tuleneb ka lisatud täht K. Must värv aitab kergemini luua neutraalseid halle ja tumedaid toone.

Värviring

Seoseid kolme erineva põhivalguse (RGB) ja kolme põhivärvi (CMY) vahel saab piltlikult kujutada allpool toodud värviringi abil. Näiteks magenta saab tekitada tema kahe naabervärvuse red ja blue segunemisel. Yellow ja cyan annavad segunedes rohelise (green).Kahte värvust, mille liitudes tekib valge värvus, nimetatakse teineteise suhtes täiendvärvusteks. Värviringil asuvad täiendvärvused vastakuti ja on ühendatud mustade nooltega.

Kui näiteks foto printimisel selgub, et see on liiga roheline, aitab magenta lisamine. Punase saa