| Cristy | 96bc886 | 2020-03-23 17:56:00 -0400 | [diff] [blame] | 1 | Now that ImageMagick version 7 is released, we continue to maintain the legacy |
| 2 | release of ImageMagick, version 6, at https://legacy.imagemagick.org. Learn how |
| 3 | ImageMagick version 7 differs from previous versions with our porting guide. |
| 4 | |
| 5 | We discovered a bug in the pseudo-random generator prior to ImageMagick |
| 6 | 7.0.9-11, the first 3 values repeated because the random state was not |
| 7 | initialized properly. As a consequence of the fix, expect a different |
| 8 | numerical sequence when seeding (-seed). |
| 9 | |
| 10 | ImageMagick best practices strongly encourages you to configure a security |
| 11 | policy that suits your local environment. |
| 12 | |
| 13 | The ImageMagick development process ensures a stable API and ABI. Before each |
| 14 | ImageMagick release, we perform a comprehensive security assessment that |
| 15 | includes memory error, thread data race detection, and continuous fuzzing |
| 16 | to detect and prevent security vulnerabilities. |
| 17 | |
| 18 | As an analog to linear (RGB) and non-linear (sRGB) color colorspaces, as |
| 19 | of ImageMagick 7.0.7-17, we introduce the LinearGray colorspace. Gray is |
| 20 | non-linear grayscale and LinearGray is linear (e.g. -colorspace linear-gray). |
| 21 | |
| 22 | Want more performance from ImageMagick? Try these options: |
| 23 | |
| 24 | add more memory to your system; |
| 25 | add more cores to your system; |
| 26 | reduce lock contention with the tcmalloc memory allocation library; |
| 27 | push large images to a solid-state drive, see large image support. |
| 28 | |
| 29 | If these options are prohibitive, you can reduce the quality of the image |
| 30 | results. The default build is Q16 HDRI. If you disable HDRI, you use half |
| 31 | the memory and instead of predominately floating point operations, you use |
| 32 | the typically more efficient integer operations. The tradeoff is reduced |
| 33 | precision and you cannot process out of range pixel values (e.g. negative). If |
| 34 | you build the Q8 non-HDRI version of ImageMagick, you again reduce the memory |
| 35 | requirements in half-- and once again there is a tradeoff, even less precision |
| 36 | and no out of range pixel values. For a Q8 non-HDRI build of ImageMagick, |
| 37 | use these configure script options: --with-quantum-depth=8 --disable-hdri. |