Raster color

As the graphical capabilities of the computer systems became more powerful simultaneously the number of visualized structures increased. With the introduction of raster graphics (1974) and colored raster graphics displays (1979), other forms of molecular representations were possible [197]. CPK models could be represented and colored bonds or molecular surfaces could be visualized. 

Farb-messer, m. colorimeter, -messung, /. colorimetry, -mine, /. colored lead (for pencils). -mischer, m. color mixer. mittel, n. coloring agent, -miihle, /. color mill, -muster, n. color pattern color sample, -nuance, /. color shade, tint, -pflanze, /. dye plant, -rakel, rn.. f. color doctor, -raster, m. color screen, -reaktion, /. color reaction. 

We have kept the data collection computer and its software simple and economical. The computing power and peripherals needed to provide high quality plotting and data reduction are available on a 32-bit minicomputer that supports a number of our projects. The floppy discs from the data collection process can be read directly into the data reduction computer. Special menus have been set up to facilitate plotting of the data on a high speed color raster display or on a high-quality multicolor pen plotter. 

The first graphical representation using MATLAB software is that of a two-dimensional contour surface plot of the data from Table 75-1 [2], This Figure 75-3 plot can represent multiple levels of j-axis data (absorbance) by the use of contours and color schemes. The MATLAB commands for generating this image are given in Table 75-2 where A represents the raster data matrix shown in Table 75-1. 

Color raster devices A raster device can map an array stored in memory on to the screen so that the value of each element of the array controls the appearance of the corresponding point on the screen. It is possible to draw... 

The DMSO induced increased blood flow was measured using the moorLDI laser Doppler imager (Moor Instruments Ltd, Devon, UK). The instrument scans a low power laser beam in a raster pattern over the skin. Moving blood in the microvasculature causes a Doppler shift, which is processed to build up a color-coded image of cutaneous blood flow. The mean and standard deviation of the blood perfusion units in a region of interest was calculated. 

The displays used in the last section are usually raster devices due the the need for a variety of colors or shading options. The resolution of... 

The CRT displays are usually vector devices, usually of high resolution (1024 x 1024) to provide clean lines. Raster equipment with its lower resolution and "jaggies" does not provide any advantage until we add the complexity of the solid fill for surfaces, or a range of colors. Hardcopy - frequently pen plotters -is a normal requirement. 

Color is another factor in raster displays. Using vector systems we were limited to a single color against a dark background, here we have more flexibility. By adding more memory in the form of additional planes, we can store more information about each pixel. With only one plane, we can tell if that pixel should be illuminated or not, giving a monochrome black-and-white display. The second plane... 

There are three Tektronix terminals that are emulated, the 4010, 4014 and 4027. The 4010 is a high resolution terminal with cross hair cursors for graphics input, the 4014 adds a hardware line patterns, choice of character sizes and user definable character sets with local storage for commonly used structures. The 4027 is a color raster terminal with 64 colors, 16 character fonts, as well as polygon and vector commands. 

From the areas of this Green River shale sample that were examined in detail using the slow rastering microprobe technique, we have chosen three for discussion. Area A was a dark band located near the 6000-/xm position in Figure 1. Area B was in the wide, lighter colored area located at 13,000 fim, and area G included a black, organic strip at 16,000... 

The cathode ray tubes are scanned in a raster like a television picture. Each scan line is modulated into a series of dots called picture elements (abbreviated to pixels or pels) and each character is built up from these pixels. It soon became possible to manipulate the pixels individually so that as well as characters, dots, lines and shapes could be displayed on the screen. Microcomputers are now available with graphics capabilities rivalling those found on mainframe systems, but at a fraction of the cost. Clearly, more memory locations have to be put aside for graphics displays. For example, compare the text (character) display of the IBM Color/Graphics display with its high-resolution monochrome graphics mode. The 80-character mode puts 25 rows of 80 characters on the screen. Each character is stored in two bytes - one for the character itself and one for its attributes , that is, colour. 

Color raster devices A raster device can map an array stored in memory on to the screen so that the value of each element of the array controls the appearance of the corresponding point on the screen. It is possible to draw each atom as a shaded sphere, or to simulate the appearance of the Corey-Pauling-Koltun (CPK) physical models to maintain most of the famihar color scheme (i.e. C = black, N = blue, O = red, P = Green, and S = yellow). In such representation, atoms are usually opaque, so that only the front layer of atoms is visible. However, clipping with an inner plane or rotation can show the packing in the molecular interior. 

If conversion for printing is done by software for raster image processing, then this, as well as the format in which the converted file is saved, can also be a source of color shift. 

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