PixelsPixels can be assorted into two definitions on where it can be seen as aphysical point within a raster image or it can be the smallest addressableelement in a display device. This would mean that the pixel itself would bethe smallest controllable element within the picture on the screen.Picture Element is originally where the term pixel came from. Pictures aredisplayed by a graphics monitor which are put together by either thousandsor millions of tiny dots which make up the image. They are all arranged inboth columns and rows and are so close together that they seem connectedwhen really they are not.
Colour Depth plays a very huge partwithin the picture up on screen andthe pixels. The number of bits whichis used to represent each pixel willdetermine exactly how many coloursor shades of grey can be displayed toproduce a final image.Colour Depth No. of colours1 Bit Colour 22 Bit Colour 44 Bit Colour 168 Bit Colour 25624 Bit Colour 16,777,216colours ortruecolour
Determining Colour Depth – Knowing that each individual bit represents 2colours, it all makes it easy to work out exactly how many colours and thevarious colour depth are in each bit. The easiest way to work out thecolours is by 2 to the power of the number of bits per pixel. For example:A Colour Depth of 4 bits would be:2 x 2 x 2 x 2 = 16 ColoursA Colour Depth of 8 bits would be:2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 256 ColoursA Colour Depth of 24 bits would be:2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x2 x 2 = 16,777,216By multiplying 2 by the number of the bits would then give you how manycolours you would get within an image on screen.
ResolutionResolution itself refers to the sharpness and the clarity of animage. The term is usually most often used to describemonitors, printers and bit-mapped graphic images. Things suchas printers, monitors, scanners and other possibly I/O(input/output) devices in many cases can be classed as eitherhigh resolution, medium resolution or low resolution.Bitmap images are made up of thousands if not millions ofpixels. The resolution for an image is very simple; it’s thenumber of PPI (Pixels Per Inch) in the bitmap grid. Theresolution is a main aspect for a bitmap image. Knowing theresolution is the PPI of an image, the width and height is alsoanother aspect in which makes up a bitmap image which wouldbe the size. By combining these two factors together, you candetermine how many pixels it takes to make the image.
There are typical resolutions which vary from different resolutions and where they areused. For example: The resolution 256x256 is found on cameras which are cheap and produce very lowquality images which are either too pixelated or just not to a standard people wishto have images. The resolution 640x480 is the kind of resolution which is acceptable and consideredas the ideal resolution for e-mailing images and posting pictures on websites. The resolution 1216x912 is the kind of resolution which is good for printing imagesthat you want to print off. It is considered a ‘megapixel’ image size. The resolution 1600x1200 is one of the ‘high resolution’ of resolutions. With around2 million pixels which are used to create an image. This is the resolution whichwould enable you to print off an image 4x5 inch and still have the photo quality asyou would in a photo-lab. The resolution 2240x1680 is the kind of resolution which would be found on 4megapixel cameras which is the current standard. This resolution allows images tobe printed larger than the 4x5 inches to 16x20 inches and still have a great quality. The resolution 4064x2704 is a top quality resolution which would be classed as topof the range. This is the kind of resolution which would have images produced by atop of the line digital camera with 11.1 megapixels. By having this kind of resolution,you can create images at 13.5x9 inches and still have an excellent outcome onimages as there is no loss on the picture quality.
Screen RatiosThe aspect ratio of an image is the best way in which to describe theproportional relationship between both its width and its height.The Aspect Ratio is mainly set out with two numbers separated by acolon, for example 16:9. The best way to get the aspect ratio byusing an x:y aspect ratio example, is to divide the width by x units ofboth equal length and also that the height is measured using thesame length unit. Then after that the height will then be measuredusing the y units.
Films within aMovieTheatreHighDefinitionTelevisionStandardAspectRatio/StillPhotographyVideoGraphicThere are two main common aspect ratiosused today in the presentation of films anda slight example of these are placed withinthe image on the bottom right of the page.They are 1.85:1 and 2.39:1. These are usedto give the audience a greater viewingexperience in the film that they will begoing to see. Whereas if we was looking atthe two aspect ratios which seem to be themost common for video graphic, it wouldbe sized smaller which you would be ableto use in the comfort of your own home.With the aspect ratio 4:3 and 16:9 for thevideo graphic use, the 4:3 aspect ratio alsois the standard aspect ratio and is mostcommonly used especially within stillphotography. With the 16:9 aspect ratio,this is the universal video format of the20th century as well as the universal high-definition standard television andEuropean digital television.
Frame RateFrame rate which can also may be known as frame frequency isbasically the frequency (rate) which an imaging device willproduce a unique consecutive images what are called frames.The frame rate itself is often seen as FPS (Frames Per Second).
Each individual film which has been made, isthe illusion which is created by thousands ofstill images in rapid succession. The frame ratewhich has already been mentioned is whatdescribes both the speed of recording and thespeed of the playback. If there are moreframes which have been recorded, then thatmeans the motion is more accuratelydocumented onto the recording medium.
Video FormatsThere are many different sections within video formatswhich can be looked at to define how a video is recordedand stored. The many different sections consist of;Codec/CompressorFrame RateFrame SizeFrame Aspect RatioPixel Aspect RatioScanning Method (Interlaced or Progressive)
Different Video Formats Used
There are many different video formats but the most commonformats are:AVCHD (Advanced Video Codec High Definition).AVI (Audio Video Interlaced).FLV (Flash Video Format.MPEG (Motion Picture Experts Group)MPEG-4 (.MP4).WMV (Windows Media Video).MOV
The video format AVCHD is a high end and high-definition format whichSony and Panasonic developed originally for the reasons as people couldhave high definition in their very home. The format itself isn’t the bestformat for sharing due to the excessive file size which makes itunsuitable. The AVI format was developed by Microsoft and has beenaround as long as digital video has been. It is a long-standard format andthe file itself tends to be very big which means this that the internet isnot compatible for this type of file as well as uploading the file tosomeone. Now where the first two formats fail for sharing files on theweb, this is where the format FLV comes in because this is the mostcommon format for uploading and sharing things on the web today. Thevideos have a file extension which is encoded by Adobe Flash softwarewithin the Adobe Flash Player. Motion Picture Expects Group developedthe format MPEG which was establish in 1988. It was established todevelop standards for the digital audio and video formats. MPEG-4 is justanother great format which enables people to share things on theinternet. With it being only a small file size, comparing the format itselfto other video formats the same size as this, this looks more clean.
The Windows Media Video (WMV) is the format which is used fornot only streaming contents via the internet, but also enables thecontents to be downloaded. The only problem with the WMV is thatthe file size is a rather small size, and it one of the smallest file sizesthere is and this means that the videos within this particular formatwill lose their quality in a hurry because it is so small. It does notmatch the standard of the modern codecs. One of the most commonsharing video formats is MOV and it is an extension which is used toidentify an Apple Quick Time Movie. This format is especially usedamongst Mac users and is considered as one of the best looking fileformats. The file size for MOV is extremely big and one of the mainreasons for this is that Quick Time hasn’t been a Mac-only program.There are Quick Time versions an players which exist on many PCs.
CompressionCompression or decompression is enabled by a video codec which caneither be a device or software. The term codec is short for coder-decoder. This particular term describes the method in which the videodata is encoded into a file and then it is decided when the file hasbeen played back.
When one codec is in the process of being converted into another codec, the termfor this is transcoding. A codec itself can either be two things, it can be Lossless orLossy. The difference between the two is: Lossless – Lossless Data Compression allows exact original data to bereconstructed from the compressed data. Lossy – Lossy Compression is a data encoding method which compresses data bylosing or discarding parts of the data. This is so that the amount of data isminimized so it can be handled by a computer.