ha1 - motion graphics now

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1. Pixels In order for any digital computer processing to be carried out on an image, it must first be stored within the computer in a suitable form that can be manipulated by a computer program. The easiest way of doing this is to divide the image up into a collection of discrete, tiny cells which are known as pixels In digital imaging, a pixel is a physical point in a raster image and the smallest addressable element in a display device. This means it is the smallest controllable element of a picture represented a screen. It is a minute are of illumination on a display screen, one of many from which an image is composed. A pixel features the closes shaded of colour as possible to an image and can be manipulated through many different means. Though each pixel can only be one colour, when put together they blend to form various shades of colour, which is what we see in a final photograph or picture. Pixels can only be viewed once zoomed in greatly. Each individual pixel is represented by a square. This is an example of a photograph with its entire pixel elements exposed. Close up, they look very strange and do not appear to be a part of the same picture. However, when they are all together they blend to form the clear image. The number of distinct colours represented by a pixel depends on the number of bits per pixel. A bit is the smallest unit of data and as a single binary value, which is either 0 or 1. Binary code is made up of 0s and 1s and is typically used for coding and passwords. For example, an 8-bit colour monitor will use 8 bits for each pixel. As can be seen from the table below, an 8 bit colour depth will be able to display 256 colours. The more bits per pixel means more colours can be shown which ultimately leads to a better looking and clearer image. This is why older pictures are grainy and of poor quality, as they did not have the technology to increase the amount of bpp (bits per pixels). The quality of a display system depends on the resolution. Each bit represents 2 colours and from this you can determine the amount of colours for various colour depths. The number of possible colours is Colour Depth 1 bit colour 4 bit colour 8 bit colour 24 bit colour No. Of Colours 2 16 256 16,777,216 or True Colour 2. 2 to the power of the number of bits per pixel. For example, a colour depth of 4 bits would be 2 times itself 4 times. So a colour depth of 4 bits would be 2 times itself 4 times. The sum is 2x2x2x2 = 16 colours. This same sum is applied for calculating all of the numbers of colours in a bit-colour depth. It can be assumed that a picture consists of huge blocks of colours but, once an image has been exposed, you can see its pixel elements. This can also allow people to see colours that are lost to discretization. Instead of film like from older cameras such as disposable cameras, a digital camera has a sensor that converts light into electrical charges. A digital camera takes light and focuses it via the lens onto a sensor. The sensor is made out of a grid of tiny things called photosites, which are sensitive to light. They are usually called pixels- a shortened term of the phrase picture elements. There are millions of these individual pixels in a sensor of a digital camera, allowing for high-quality pictures which capture millions of colours. Resolution Resolution refers to the sharpness and clarity of an image. It refers to the number of pixels/dots that make up an image. The term is most often used to describe monitors, printers, and bit-mapped graphic images. The resolution can be changed depending on different various things, so the quality can be changed. As stated above images are composed of pixels. Image resolution is simply the number of Pixels per Inch (PPI) in the image grid (technically known as a bitmap image and a bitmap grid). There are two aspects to every bitmap image - its size (width and height in inches) and resolution (the number of pixels per inch). These two factors will determine the total number of pixels in an image. Above is a series of the same image, when displayed by their resolution. As stated above resolution means the number of pixels per inch. So, as the inches are expanded the image become clearer as more pixels become prominent to form the image. For graphics monitors, the screen resolution signifies the number of dots (pixels) on the entire screen. For example, a 640-by-480 pixel screen is capable of displaying 640 distinct dots on each of 480 lines, or about 300,000 pixels. The following are examples of the most common camera resolutions: 256x256 This is usually found on very cheap cameras and the quality is often very poor. The relatively small amount of 65,000 pixels means that the picture wont have full colour qualities and sharpness. 640x480 - This is the lowest resolution on most decent camera. Though the quality still isnt very great, it can be acceptable for things such as emailing and posting pictures online. 1216x912 - This is a "megapixel" image size of about 1,109,000 total pixels. 3. 1600x1200 This is the resolution size that is considered as being of High Resolution. This means that it can have the same quality as ones created in places such as photo labs. 2240x1680 - Found on 4 megapixel cameras, this is a general standard of picture that can produce large pictures that retain a good quality. 4064x2704 This is the best type of resolution on the market, which can retain quality images up to 13x6 inches large. 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). The clarity of the image is often decided by its spatial resolution, not the number of its pixels. On the left here is a conversion of pixels to resolution sizes. Here, you can see 5 mega- pixels is the equivalent of a resolution size of 2592 x 1944. Graphics programs such as Photoshop let the user set the desired resolution for an image. A system must be able to operate the resolution sizes, or the image quality will be lost. Screen Ratios The aspect ratio of a screen or image describes the proportional relationship between its width and its height. It is commonly expressed as two numbers separated by a colon. For example: 4:3 or 16:9. Ratios always remain the same, no matter how large anyting is. For example all three images below have an aspect ratio of 16:9. They have the exact same proportions but are different sizes. If someone takes a picture using a ratio that is either proprtionally wider or taller, then the image will capture more of an image accordingly. For example a camera with a ratio of 16:9 will have a wider range, meaning it would be better for things such as landscape shots. 4. An aspect ratio is a form of screen ratio. Aspect ratio is the ratio of width to height of an image. A 4:3 aspect ratio means that for every 4 inches of width in an image, you will have 3 inches of height. In mathematical terms, that comes out to the screen being 33% wider than it is high. This means that a 16:9 aspect ratio has 16 inches of width and 9 inches of height, making it around 77% wider. The 16:9 format is often adopted by film producers, to make their films bigger and more attractive. As conversion from theatres to TV and DVDs will be great, to retain quality some of the picture may be cut out. This could be done either by zooming or cropping. The above is from the theatrical release of a film and below is from the release on Netflix. When converting a large film for DVD, black bars will often be placed at the side or bottom of the screen according to the aspect ratio. This is done to retain the original film quality. Neflix cut out the bars and cropped segments of the film out to fit the screen. This was done for looks, as they believed a screen to be more attractive without the bars. However, cutting them out meant the screen looked stretched and would lose some components from the film. As shown on the left, the character on the right has been cut and the scene looks much smaller. Many digital cameras give people the option to change a screen ratio, allowing for either a more width-based or height-based shot. For example, someone who wants to take a portrait photo will most likely opt for 4:3, while someone looking for a landscape shot will most go for 16:9. This is because they will get more of what they want in their respective shots. Frame Rates Frame rate is the measure of the number of frames displayed per second of animation in order to create the illusion of motion. The higher the frame rate the smoother the motion of the footage, as there are more frames per second to display the numerous transitions between the constant flow of images. Early silent films had a maximum frame rate of around 14 to 24 FPS which was enough for the sense of motion, but it would appear very jerky and sped up. Frame rate describes both the speed of recording and the speed of playback. The more frames recorded per second, the more accurately motion is documented onto the recording medium. Here is an image illustrating the types of frames in 1 second of animation. Options such as those of 12fps will restrict smoothness and look like it is constantly being broken up, appearing to be a generally poor film with bad continuity errors. However, 60 fps will make the motion appear smooth 5. and the quick flow of frames will make the transitions between visual images appear natural. His is because the device using that amount of frames will capture more movement. Original silent films usually only featured a few people and so the footage doesnt look that bad as it only appears jerky when a character makes fast movements. Cameras used to film those scenes would not now be able to capture fast moving things such as cars, as the fast movement would not allow it to be captured smoothly in a limited amount of frames. If someone w