Lossy Compression
Lossy Compression (Perceptual Data Reduction)
Lossy compression achieves much smaller file sizes by permanently discarding image data that is less perceptible to human vision. JPEG, WebP lossy, and AVIF use this approach to achieve 10:1 to 50:1 compression ratios.
รายละเอียดทางเทคนิค
JPEG lossy compression applies DCT to 8x8 pixel blocks, then quantizes frequency coefficients based on quality settings. Higher quantization discards more high-frequency detail, reducing file size but introducing visible artifacts.
ตัวอย่าง
```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);
```
รูปแบบที่เกี่ยวข้อง
เครื่องมือที่เกี่ยวข้อง
C
Compress Image
R
Resize Image
C
Crop Image
R
Rotate Image
F
Flip Image
C
Convert Image
W
Watermark Image
S
SVG to PNG
I
Image to Base64
R
Round Corners
A
Add Border
I
Image Filters
A
Adjust Image
B
Blur Image
S
Sharpen Image
M
Make Square
G
Grayscale Image
S
Sepia Image
P
Pixelate Image
S
Strip Image Metadata