openmultimedia.imagewatchdog 1.0b1

Patent issues

Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace GIF (Graphics Interchange Format) as an image-file format not requiring a patent license.

Even as the JPEG compression used in various image file formats has been subject to a number of patent issues by well-known patent trolls of the industry for many years, there is currently no patent-free alternative for these formats (WebP has been available for some time, but is currently only supported by Google Chrome and Opera web browsers).

Configure

• Go to ‘Site Setup’.

• Select ‘Image WatchDog’.

• Select the files formats that should be converted to PNG.

• You can choose to optimize the PNG file checking the ‘Optimize PNG’ checkbox.

• ‘Migration delay (milliseconds)’ and ‘Transaction threshold’ are only used for migration.

• Activate the on-fly convertion checking the ‘Enabled’ checkbox.

Migrate images

• First Configure.

• Now in the ‘Image WatchDog’ control panel you can set:

  • ‘Migration delay (milliseconds)’, this parameter indicates a delay between every processed image. 0 means no delay, more fast, but CPU intensive, bigger values are nicer with the CPU but will slow down the process.

  • ‘Transaction threshold’, this parameter is the number of images processed in a single transaction. 0 means one single transaction, more fast, but RAM intensive, small values are nicer with the RAM but will slow down the process.

• Click on ‘Save & Migrate’ button to start the migration process.

• Get your prefered caffeinated beverage because this could take some time, you could check your logs to see the progress of migration process.

Script to migrate images

The package includes a handy method to migrate images, sometimes prefered for running long processes.

• From your command line run: instance run <path_to_openmultimedia.imagewatchdog_package>/openmultimedia/imagewatchdog/script/install_and_migrate.py <plone_site_name>

• This will install de product in the Plone site and migrate the images to PNG.

• Get your prefered caffeinated beverage because this could take some time, you will see the progress of migration process in your console.

GIF

• On small images, GIF can achieve greater compression than PNG.

• GIF intrinsically supports animated images. PNG supports animation only via unofficial extensions.

JPEG

• JPEG formats can produce smaller files than PNG for photographic (and photo-like) images, since JPEG uses a lossy encoding method specifically designed for photographic image data.

1.0b1 (2012-12-19)

• Initial release.