Image Resolution and Output chapter seven Basic Concept

Image Resolution and Output chapter seven

Basic Concept of Digital Output �Each of profession and industries in which three-dimensional computer imaging is used today – for example, live action movies, TV animation, and platform games – has different output requirement. �This is due to the differences in the final product and the different forms of final delivery and distribution of products in each of these area. chapter seven

Cont. . �The digital output process starts when rendered images are taken out of the computer system with the output peripherals. �This include an array of devices such as printers, pen platters, film or video recorders etc. chapter seven

Cont. . �Output peripherals are used for fixing the images created on the monitor onto other media that may include paper, film, video and CD-ROM �This capture process is not automatic. �It is based on a translation data. chapter seven

Cont. . �This translation is made by software and electronic components of output peripherals call digital-toanalog converters or DTAs. �The DTAs convert the digital information created with software back into continuous information. �This process is just the inverse of scanning an image on paper that is to be used as a texture map or a background in a three dimensional scene. chapter seven

Image Resolution �Image resolution 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. chapter seven

Cont. . �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, or TV lines), or to angular subtenant. chapter seven

Cont. . �Image resolution can be divide to four categories: �Spatial resolution �Pixel resolution �Temporal resolution �Image compression chapter seven

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. chapter seven

Cont. . �In Stereoscopic 3 D images, spatial resolution could be defined as the spatial information recorded or captured by two viewpoints of a stereo camera (left and right camera). chapter seven

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

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. �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. chapter seven

Cont. . 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). chapter seven

Cont. . �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. chapter seven

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 colour components relative to each other or mix up temporal with spatial resolution. chapter seven

Cont. . Digital Camera LCD Display chapter seven CRT Display

chapter seven