# ETC2 yields strange artifacts around semitransparent regions

**URL:** <https://forums.imgtec.com/t/etc2-yields-strange-artifacts-around-semitransparent-regions/4153>\
**Category:** Uncategorized\
**Tags:** pvrtextool\
**Created:** [April 8, 2025, 1:28pm UTC](https://forums.imgtec.com/t/etc2-yields-strange-artifacts-around-semitransparent-regions/4153 "2025-04-08T13:28:25Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dmarker22](https://avatars.discourse-cdn.com/v4/letter/d/e0b2c6/32.png) [@dmarker22](https://forums.imgtec.com/u/dmarker22)\
**Post date:** [April 8, 2025, 1:28pm UTC](https://forums.imgtec.com/t/etc2-yields-strange-artifacts-around-semitransparent-regions/4153/1 "2025-04-08T13:28:25Z")

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Hello!

I’m upgrading the PVRTexToolCLI.exe tool from 4\_20\_0\_0 to 5\_6\_0\_0 and am noticing strange artifacts around the semi-transparent regions of an image with the 5\_6\_0\_0 version.

Here are the simplified arguments I am using:

> PVRTexToolCLI\_5\_6\_0\_0.exe -i music.png -f ETC2\_RGBA -q ETCFAST -p -o music\_5\_6\_0\_0.pvr  
> PVRTexToolCLI\_4\_20\_0\_0.exe -i music.png -f ETC2\_RGBA -q etcfast -p -o music\_4\_20\_0\_0.pvr

Here are how the rendered .pvr files look in PVRTexToolGUI.exe (this matches my OpenGL ES output).

Am I missing something when using 5\_6\_0\_0?

Thank you,  
-Dave

 ![image](https://us1.discourse-cdn.com/flex015/uploads/imagination1/original/1X/effd6a57936c446aa42fa5f0342431ed86fa9dd6.png)

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<div class="post-metadata">

**Author:** ![dmarker22](https://avatars.discourse-cdn.com/v4/letter/d/e0b2c6/32.png) [@dmarker22](https://forums.imgtec.com/u/dmarker22)\
**Post date:** [April 8, 2025, 7:53pm UTC](https://forums.imgtec.com/t/etc2-yields-strange-artifacts-around-semitransparent-regions/4153/2 "2025-04-08T19:53:59Z")

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I’m pretty sure this is related to: [Unwanted discard of colors when alpha is zero](https://forums.imgtec.com/t/unwanted-discard-of-colors-when-alpha-is-zero/3907)

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**Author:** ![AlejandroC](https://avatars.discourse-cdn.com/v4/letter/a/97f17d/32.png) [@AlejandroC](https://forums.imgtec.com/u/AlejandroC)\
**Post date:** [April 11, 2025, 11:38am UTC](https://forums.imgtec.com/t/etc2-yields-strange-artifacts-around-semitransparent-regions/4153/3 "2025-04-11T11:38:45Z")

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Hi dmarker22,

Thanks for your message.

You are right, as mentioned in [Unwanted discard of colors when alpha is zero - #7 by AlejandroC](https://forums.imgtec.com/t/unwanted-discard-of-colors-when-alpha-is-zero/3907/7) it is a known issue and present in the latest PVRTexTool release. The last PVRTexTool release where this issue is not present is v4.23 from the 2019.2 release.

You can find the installer in our Developer Portal (under [Previous Releases - Imagination Developers](https://developer.imaginationtech.com/downloads/previous-releases/) → PowerVR Offline Installers → 2019 R2)

Best regards,  
Alejandro