it still has the forex tick data feed 'leakage' problem of the ' Shepards ' method, so lets look at this problem in more detail. Convert -size 160x140 plasma:fractal -blur 0x2 -swirl 180 -shave 20x20 plasma_g Greyscale Plasma Now the plasma generator will always generate color, even on a pure black solid color. You can not simply shift the position of the middle color, except by roughly modifying the input gradient to some non-linear form, so as to shift that center. By default the seed is randomized when IM starts, so you normally do not need to randomize it yourself using " seed " to get a random result. The result is a simple linear gradient over which you have a lot of control. Convert flux_f -function Sinusoid.5,0 flux_rippled_f You can also animate the ripples within the animation. But further processing, particularly on the black background version, will let you enlarge the dots based on their gray-scale intensity or generate streaks and or star flares from those dots. Convert -size 100x60 radial-gradient: rgradient_g This lets you easily generate a square radial gradient from the center to a corner by making one edge.42 (square root of 2) times larger, and crop. Blurred Random Images (random blobs) Now while you can make direct use of random images to create speckled effects, purely random images are generally not very useful.
Normalizing a prefect 50 grey plasma will produce a particularly uniform multi-color plasma image, over the full range of colors, including white and black. This can be done by converting that existing image into the canvas needed, but preserving the image's original size. If you want to preserve transparency either set "-background none" or "-compose SRC" (see Src Compose Method for details). To the left is a test image. Convert g -alpha off -fx Gold color_fx_f The " -fx " operator will even let you do a little color mathematics. Providing the " convert g -level 100,100 -alpha off black_g -fx" operator provides a more obvious way of creating a black canvas by clearing all the pixels to zero. Interpolated lookup gradients can also be expanded to 2 dimensions, and generate square linear gradients ( Bilinear Interpolation just as easily as purely one dimensions gradients. Essentially it is using a faster image resizing technique to generate the blurred layers of the previous example.