JPEG Image Compression
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JPEG is a lossy image compression algorithm, not a file format. It uses a 4-step process to compress images: 1) transforming RGB to YCbCr color space, 2) applying a discrete cosine transformation to identify redundant data, 3) quantizing the remaining data, and 4) encoding the result to minimize storage requirements. Typical compression ratios are 10:1 to 20:1 without visible loss and up to 100:1 compression for low quality applications.
JPEG Image Compression
- 1. JPEG Image Compression BITS GC 331 Computer Projets HemanthKumar Mantri 2004S3P7549
- 2. JPEG Image Compression JPEG: Joint Photographic Experts Group. JPEG: compression algorithm, NOT a file format. The original JPEG format was JFIF and later SPIFF. Current popular choices include C-Cube JFIF; Adobe TIFF/JPEG. 4-step process: 1. Transforming RGB to YCbCr, separating intensity from color 2. Identifying redundant data using a Discrete Cosine Transformation (DCT) 3. Quantizing remaining data 4. Encoding the result to minimize storage requirements
- 34. RGB YCbCr
- 35. After DCT After Quantisation
- 37. Inverse Quant. IDCT
- 38. YCbCr New RGB New
- 39. Original 37.7 KB Regenerated 29.3 KB Difference
- 40. Compression performance JPEG: } 10:1 to 20:1 compression without visible loss (effective storage requirement drops to 1-2 bits/pixel) } 30:1 to 50:1 compression with small to moderate visual deterioration } 100:1 compression for low quality applications
- 42. That’s all And Thank You