2014 Fiscal Year Final Research Report
High-resolution Image Compression Using Haar Transform with Gradient Estimation
| Project/Area Number |
24560532
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Measurement engineering
|
|---|
| Research Institution | Meijo University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2012-04-01 – 2015-03-31
|
| Keywords | 非可逆画像圧縮 / ハール変換 / 予測残差 / 高精細画像 |
|---|
| Outline of Final Research Achievements |
The most popular lossy image compression scheme is the JPEG standard for still images and the MPEG standard for video sequences. Although some new standards are emerging, many systems including digital cameras and image databases still use the JPEG standard, which is based on the Discrete Cosine Transform (DCT).
In this research, we proposed a new lossy image compression-decompression method that reproduces images with lower entropy (bit rates), particularly for high-resolution images, than those processed by the DCT-based method at the same PSNR values. Our approach is to predict each block using a gradient estimation, followed by applying an orthogonal transformation to the prediction error. The proposed method is based on the Haar transform that requires only O(N) operations for an input signal of length N while the DCT requires O(N log2 N) operations. This advantage is particularly significant for the high-resolution case.
|
| Free Research Field |
数値計算
|
