Chroma Subsampling
Chroma Subsampling (Color Resolution Reduction)
Chroma subsampling reduces the color resolution of an image while preserving full brightness (luminance) detail. Human eyes are less sensitive to color changes than brightness changes, making this an efficient compression technique.
技术细节
Expressed as ratios like 4:4:4 (no subsampling), 4:2:2 (half horizontal color resolution), and 4:2:0 (quarter color resolution). JPEG typically uses 4:2:0, reducing file size by 50% compared to 4:4:4.
示例
```javascript
// Image compression via Canvas
canvas.toBlob(
blob => console.log(`Size: ${(blob.size/1024).toFixed(0)} KB`),
'image/jpeg',
0.8 // quality: 0.0 (smallest) to 1.0 (best)
);
// WebP output (25-34% smaller than JPEG)
canvas.toBlob(cb, 'image/webp', 0.8);
```
相关格式
相关工具
相关术语
Metadata
Rasterization
Resolution
DPI
Color Space
Alpha Channel
Lossy Compression
Lossless Compression
EXIF
Color Profile
Bit Depth
Vector Graphics
Raster Graphics
HDR
WebP
AVIF
Sprite Sheet
Thumbnail
Crop
Resize
Image Optimization
Image Histogram
Noise Reduction (Image)
Panorama Stitching
Image Segmentation
Object Detection
Feature Matching
Image Interpolation
Dithering (Image)
Alpha Compositing
Image Pyramid
Mipmap
Texture Atlas
Image Registration
Morphological Operations
IPTC
ICC Profile
Gamut Mapping
Tone Mapping
Chromatic Aberration
Vignetting
XMP
Color Grading (Image)
Focus Stacking
Content-Aware Fill
Batch Resize
Aspect Ratio
Chroma Key
Convolution
Canvas
Compression Artifact
DPI/PPI
Gamma
Histogram