# How to change noVnc image quality/compression

**URL:** <https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339>\
**Category:** Get Help\
**Created:** [May 10, 2019, 1:08pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339 "2019-05-10T13:08:59Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![ssivy](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/ssivy/32/106_2.png) [@ssivy](https://discourse.openondemand.org/u/ssivy)\
**Post date:** [May 10, 2019, 1:08pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/1 "2019-05-10T13:08:59Z")

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I’m wondering if there is any settings to make the interactive desktop apps a little more crisp looking. While they look fine, I do notice some pixelation around images and text. Since most users will be on the local LAN, is there any option to turn down/off image compression or other ways to trade for better image quality.

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**Author:** ![efranz](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/efranz/32/27_2.png) [@efranz](https://discourse.openondemand.org/u/efranz)\
**Post date:** [May 10, 2019, 2:50pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/2 "2019-05-10T14:50:52Z")

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It appears that this might be controlling compression and quality:

> <https://github.com/OSC/ood-dashboard/blob/master/public/noVNC-1.0.0/app.js#L7512-L7513>

And the `pseudoEncodingQualityLevel0` and `pseudoEncodingCompressLevel0` default values set here [https://github.com/OSC/ood-dashboard/blob/master/public/noVNC-1.0.0/app.js#L3185-L3197](https://github.com/OSC/ood-dashboard/blob/master/public/noVNC-1.0.0/app.js#L3185-L3197)

I don’t know understand VNC protocol enough yet to know what the values mean (is quality9 high and quality0 low? is compress0 no compression and compress9 max compress? so would maximum quality be quality9 compress0? or are these independent variables if lossless compression is being used?).

But possibly playing with the default value or the magic numbers being added to it in the `_sendEncodings` function could result in a more desirable outcome. If that was the case, we could look at parameterizing these values and making the modification of this controllable from the launch interface.

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**Author:** ![rodgers.355](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/rodgers.355/32/193_2.png) [@rodgers.355](https://discourse.openondemand.org/u/rodgers.355)\
**Post date:** [June 5, 2019, 8:56pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/3 "2019-06-05T20:56:37Z")

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@ssivy we ended up looking into this and have a prototype that allows changing quality settings at VNC-connect-time: [https://github.com/OSC/ood-dashboard/pull/476](https://github.com/OSC/ood-dashboard/pull/476).

 ![new-controls](https://us1.discourse-cdn.com/flex015/uploads/osc/original/1X/08c5597c38a04d4624f05b783357d7c97bfe36f3.png)

It’s vacation season around here so we may be able to squeeze this into the initial 1.6 release or we may not.

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**Author:** ![jeff.ohrstrom](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/jeff.ohrstrom/32/136_2.png) [@jeff.ohrstrom](https://discourse.openondemand.org/u/jeff.ohrstrom)\
**Post date:** [July 5, 2019, 5:43pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/4 "2019-07-05T17:43:40Z")

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This is in the current release, 1.6.7.

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**Author:** ![jeff.ohrstrom](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/jeff.ohrstrom/32/136_2.png) [@jeff.ohrstrom](https://discourse.openondemand.org/u/jeff.ohrstrom)\
**Post date:** [July 5, 2019, 5:43pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/5 "2019-07-05T17:43:59Z")

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Closed on July 5, 2019, 5:43pm UTC



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**Author:** ![jeff.ohrstrom](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/jeff.ohrstrom/32/136_2.png) [@jeff.ohrstrom](https://discourse.openondemand.org/u/jeff.ohrstrom)\
**Post date:** [July 8, 2019, 8:28pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/6 "2019-07-08T20:28:04Z")

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Opened on July 8, 2019, 8:28pm UTC



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**Author:** ![westburg.2](https://avatars.discourse-cdn.com/v4/letter/w/0ea827/32.png) [@westburg.2](https://discourse.openondemand.org/u/westburg.2)\
**Post date:** [May 26, 2022, 3:19pm UTC](https://discourse.openondemand.org/t/how-to-change-novnc-image-quality-compression/339/7 "2022-05-26T15:19:05Z")

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Closed on May 26, 2022, 3:19pm UTC