Sampling & reconstruction

Technique

Intermediate

Mipmaps

Precompute lower-resolution versions of a texture so minified sampling becomes far less aliased and unstable.

graphics

sampling

textures

aliasing

Interactive playground

Tweak the operator or scene live so the article connects to an immediate visual result.

Mipmaps

Pre-average the texture into lower-resolution levels so minification stops aliasing the full-resolution pattern.

High-frequency texture

Reference view

Single level vs mip chain

Interactive compare

Both halves shrink the same texture, but only the right half samples a prefiltered mip level.

Minification 0.18

Family

Sampling & reconstruction

Resampling images, choosing mip levels, and reconstructing signals across scales.

Builds on

1 topic

Read these first if you want the surrounding pipeline context.

Unlocks

1 next topic

Use these follow-ups when you want to keep turning the image-processing pipeline forward.

Learning paths

This topic appears in curated graphics progressions so the next step is obvious.

Choose this over that

Pick a better scale before reconstructing

Mipmaps solve a different problem than bilinear or bicubic interpolation: which resolution to sample from before you even start reconstructing.

Current topic

Mipmaps

Choose this when: Textures are being minified and aliasing or shimmer is the main concern.

Choose something else when: Only one scale is involved and reconstruction quality is the main question.

Sampling & reconstruction Open topic

Bilinear and Bicubic Interpolation

Choose this when: The issue is how to reconstruct between samples at a chosen scale.

Choose something else when: The texture is shrinking enough that a different mip level is essential.

Post-processing Open topic

Temporal Anti-Aliasing (TAA)

Choose this when: Temporal instability survives even after spatial filtering and mip selection.

Choose something else when: The artifact is mainly static texture aliasing.

Problem

A texture can contain far more detail than one screen pixel can display. If you sample the full-resolution texture directly while it shrinks on screen, the result shimmers, aliases, and crawls.

Intuition

Mipmaps build an image pyramid. Each level is a lower-resolution, prefiltered version of the one before it. When a texture is minified, sample from a level that roughly matches the screen footprint instead of forcing one pixel to decide among huge high-frequency detail.

Core idea

Generate a chain of half-resolution images until the texture becomes tiny.
Estimate the texture footprint in screen space at sample time.
Choose one mip level or blend between adjacent levels before applying ordinary interpolation within that level.

Worked example

A dense checkerboard viewed far away will shimmer if sampled only from its highest-resolution level. With mipmaps, the renderer switches to a pre-averaged level so the distant surface looks stable instead of flickering.

Complexity

Mip generation costs extra memory and preprocessing, but lookup remains constant-time per sample once the pyramid exists.

When to choose it

Choose mipmaps whenever textures can become much smaller on screen than their native resolution.
Bilinear or bicubic interpolation alone is not enough when the source is being strongly minified.
Use temporal AA later when some instability remains after good spatial filtering and mip selection.

Key takeaways

Mipmaps fight minification aliasing by changing the source scale before interpolation.
They are a scale-selection tool, not merely another interpolation mode.
They greatly reduce shimmer on textured surfaces.
Real-time rendering pipelines almost always rely on them for texture stability.

Practice ideas

Render a repeated checkerboard with and without mipmaps while shrinking it on screen.
Inspect which mip level is chosen at several viewing distances.
Compare remaining shimmer with and without a temporal stabilizer such as TAA.

Relation to other topics

Interpolation determines how one mip level is sampled once chosen.
Gamma-aware filtering matters when building or sampling color textures.
TAA can complement mipmaps when temporal instability survives after proper texture filtering.