Last update: 2021-10-12
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  • Developer

[ZoomView.|<containerId>_zoomView.]enableHD=always|never|limit[, *number*]


Enable, limit, or disable optimization for devices where devicePixelRatio is greater than 1, that is devices with high-density display like iPhone4 and similar devices. If active then the component limits the size of the IS image request as if the device only had a pixel ratio of 1 and that way reducing the bandwidth.

See example below.


If using the limit setting, the component enables high pixel density only up to the specified limit.

See example below.






The following are the expected results when you use this configuration attribute with the viewer, and the viewer size is 1000 x 1000:

If the set variable equals



The pixel density of the screen/device is always accounted.

  • If the screen pixel density = 1, then the requested image is 1000 x 1000.

  • If the screen pixel density = 1.5, then the requested image is 1500 x 1500.

  • If the screen pixel density = 2, then the requested image is 2000 x 2000.


It always uses a pixel density of 1 and ignores the device's HD capability. Therefore, the requested image requested is always 1000 x 1000.


A device pixel density is requested and served only if the resulting image is below the specified limit.

The limit number applies to either the width or the height dimension.

  • If the limit number is 1600, and the pixel density is 1.5, then the 1500 x 1500 image is served.

  • If the limit number is 1600, and the pixel density is 2, then the 1000 x 1000 image is served because the 2000 x 2000 image exceeds the limit.

Best practice: The limit number must work with the company setting for maximum size image. Therefore, set the limit number to equal the company maximum image size setting.

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