Rasterize

Blackmagic lists Rasterize among the Resolve 21 Krokodove Image Tools and describes it as a filter effect that takes an image and converts it into dots, squares or diamonds for half-tone style imagery. The core topology therefore starts with an Image input, not an internal image generator.

The useful mental model is a virtual grid laid over the source. Rasterize samples the chosen source signal and places a repeated shape in each cell. The original image remains recognizable because its values drive the repeated elements rather than because the original pixels simply pass through unchanged.

Channel selects Red, Green, Blue, Alpha or Luminance from the main Image. This is a primary diagnostic control: a channel with strong separation produces a readable raster, while a low-contrast channel may make the pattern look nearly uniform even when the grid and shape settings are correct.

Random Seed changes the particular random realization used by jitter-related controls. It should not be treated as a substitute for Jitter Position or Jitter Angle, and animating it frame by frame can create popping rather than smooth motion.

Center X/Y define the raster-grid anchor in the frame. They are useful for aligning the pattern with a screen, title, object or layout without adding a separate downstream Transform just to change the grid phase.

Controls Size sets the overall raster-element/grid scale. Keep it conceptually separate from Shape > Size Black and Size White: the first establishes a global scale while the Black/White controls define how source values map into element size.

Angle rotates the raster structure and Controls Aspect changes its broad proportions. Establish these before adding jitter so a deliberate grid rotation is not confused with random variation.

Grid Size X and Grid Size Y control sampling/grid density along each axis. Dense grids can create moire or temporal shimmer at delivery resolution, especially after a later resize or transform, so judge frequency at 100% Viewer scale and in playback.

Shape > Type offers Circle, Square, Diamond and Shape. The built-in choices require no external image. Type = Shape activates the custom-stamp path so the green External input can provide an RGBA silhouette/texture.

The green External input is distinct from the blue Effect Mask. With Type = Shape it can provide the repeated custom stamp; with Color > Shape Color = External the same branch can supply color. Shape selection and color selection are independent decisions.

Jitter Position X/Y breaks the perfectly regular grid by offsetting stamps according to the current random seed. Small values add organic variation; large values quickly destroy source readability and can produce noisy temporal behavior.

Jitter Position After Sampling changes when positional jitter is applied relative to sampling. Public Krokodove summaries do not expose the internal formula, so the safest workflow is an A/B test on a high-contrast source with Seed and jitter values held constant.

Size Black and Size White are the core halftone mapping endpoints. They define the repeated-shape size at the dark and bright ends of the selected Channel. If the two values are nearly identical, tonal variation in element size largely collapses.

Keep Shape Horizontal separates stamp orientation from part of the overall raster rotation logic. Test it on Square, Diamond or an asymmetric custom shape; a Circle is a poor diagnostic because its orientation is visually ambiguous.

Jitter Angle adds random stamp rotation and Jitter Angle Step makes that rotation more discrete. The pair is useful for moving from rigid technical grids toward controlled randomness without immediately resorting to fully arbitrary orientation.

Shape Aspect controls the proportions of each repeated stamp and is not the same as Controls Aspect. Lock Black/White Aspect keeps the aspect response linked across tonal extremes and is a safer baseline unless brightness-dependent deformation is intentional.

Color > Shape Color chooses Solid, Image or External. Solid uses the internal swatch/RGBA values, Image derives color from the main source, and External derives it from the green auxiliary image. Geometry and color therefore do not have to use the same driver.

The Shape Color swatch plus Red, Green, Blue and Alpha controls belong to Solid mode. If Image or External is selected, changing those solid-color sliders is not the primary way to recolor the result.

Overlap selects Maximum, Add, Multiply or Screen for areas where repeated stamps intersect. Its effect becomes meaningful with larger elements, denser grids or stronger jitter that actually creates overlap.

Render > Super-Sampling ranges from 1x1 to 16x16 in the captured Resolve Inspector. It is a quality/performance control for raster edges, not an artistic strength parameter. Raise it only when small circles, diagonal edges or custom shapes visibly alias at the target resolution.

Effect Mask is an optional blue spatial gate. It limits where the already-calculated Rasterize effect is applied; it does not replace the main source channel or the custom External image.

A reliable color-halftone baseline is Image -> Luminance -> Circle -> Size Black/White -> Shape Color Image. A reliable custom-stamp baseline is Image plus an External RGBA branch, Type = Shape, then an independent choice of Solid/Image/External color.

Rasterize outputs a normal 2D RGBA image. It can feed Glow, Color Corrector, Merge, Transform or Bitmap, but it should not automatically be described as a mask stream simply because the image may look black and white.

For animation, moire and shimmer are often bigger practical risks than the still-frame look. Very fine grids, tiny shapes, diagonal angles and low supersampling may look acceptable on a paused frame but crawl during playback.

Custom external shapes are only as clean as their alpha and crop. Large transparent margins reduce the useful stamp inside each cell, while dirty alpha edges can repeat a halo hundreds of times across the frame.

Rasterize is integrated in Resolve/Fusion 21 as part of Krokodove. Do not present that exact availability or current Inspector as guaranteed for Resolve 20 or older legacy plugin builds.

Do not confuse Rasterize with simple pixelation. Pixelation groups or enlarges pixels; Rasterize reconstructs the image from repeated shapes, which is why shape type, tonal size mapping, aspect, overlap and an external stamp provide much deeper control.