Warning: This CMake source property is deprecated since 2.4, consider using ImageFiles.MCU.resourceCompression instead.

Note: Board defaults can be set using QmlProject in the BoardDefaults.qmlprojectconfig files. See Defining default variables for the platform and QmlProject Manual.

Store image in compressed format.


Without this flag set every image is stored in uncompressed format. When QUL_RESOURCE_COMPRESSION is set, an image is stored with PNG compression and will be decompressed into the cache when needed. This reduces the size of the binary but adds decompression overhead.

This flag implies that QUL_RESOURCE_CACHE_POLICY is "OnDemand".


  • The LodePNG decompression library is linked into the binary if compression is enabled for any asset.
  • Image caching must be enabled.
  • Source file properties must be set before adding files to the application using the qul_add_resource function.


This property was introduced in Qt Quick Ultralite 1.1.

See also Qt Quick Ultralite image caching, Default Resource Properties, QUL_RESOURCE_CACHE_POLICY, and qul_set_maximum_resource_cache_size.

Available under certain Qt licenses.
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