AntiqueFlaneur Posted February 17, 2021 Share Posted February 17, 2021 I've attached an .afphoto file and a transparency I exported from it. The transparency seems to have transparent holes in the section I meant to leave untouched. When I look at my .afphoto file, I can't see anything that looks like a selection/hole. Can anyone tell me why this is happening? UploadLaocoon&SonsSeaSnake.afphoto Quote Link to comment Share on other sites More sharing options...
Staff MEB Posted February 17, 2021 Staff Share Posted February 17, 2021 Hi AntiqueFlaneur, I'm having trouble reproducing this. What OS are you running? Windows 10? If you go to Affinity Photo Preferences, Performance section and disable OpenCL compute acceleration (on bottom) does it export correctly? Quote A Guide to Learning Affinity Software Link to comment Share on other sites More sharing options...
AntiqueFlaneur Posted February 17, 2021 Author Share Posted February 17, 2021 6 minutes ago, MEB said: Hi AntiqueFlaneur, I'm having trouble reproducing this. What OS are you running? Windows 10? If you go to Affinity Photo Preferences, Performance section and disable OpenCL compute acceleration (on bottom) does it export correctly? I use MacOs Big Sur. There doesn't appear to be an OpenCL Compute Acceleration option under performance preferences. Quote Link to comment Share on other sites More sharing options...
Staff MEB Posted February 17, 2021 Staff Share Posted February 17, 2021 Thanks for the info. Disable Metal compute acceleration, restart the app and check/export again. Does it fix the issue? Quote A Guide to Learning Affinity Software Link to comment Share on other sites More sharing options...
AntiqueFlaneur Posted February 17, 2021 Author Share Posted February 17, 2021 44 minutes ago, MEB said: Thanks for the info. Disable Metal compute acceleration, restart the app and check/export again. Does it fix the issue? Nope. Just as full of holes as before. Quote Link to comment Share on other sites More sharing options...
AntiqueFlaneur Posted February 17, 2021 Author Share Posted February 17, 2021 Here are my export settings, if it matters. MEB 1 Quote Link to comment Share on other sites More sharing options...
Alfred Posted February 17, 2021 Share Posted February 17, 2021 5 minutes ago, AntiqueFlaneur said: Here are my export settings, if it matters. I don’t see why it should matter, but did you have a particular reason for choosing the ‘PNG-8 (dithered)’ preset? Quote Alfred Affinity Designer/Photo/Publisher 2 for Windows • Windows 10 Home/Pro Affinity Designer/Photo/Publisher 2 for iPad • iPadOS 17.5.1 (iPad 7th gen) Link to comment Share on other sites More sharing options...
John Rostron Posted February 17, 2021 Share Posted February 17, 2021 Could it be that you used the magic wand to select then delete the background, with the contiguous box unchecked and with too high a tolerance. This would find and delete any part of the image too like your background. John Quote Windows 11, Affinity Photo 2.4.2 Designer 2.4.2 and Publisher 2.4.2 (mainly Photo). CPU: Intel Core i5 8500 @ 3.00GHz. RAM: 32.0GB DDR4 @ 1063MHz, Graphics: 2047MB NVIDIA GeForce GTX 1050 Link to comment Share on other sites More sharing options...
NotMyFault Posted February 17, 2021 Share Posted February 17, 2021 On iPad, i get the same artifacts when using PNG-8 (dithered)’ preset I found via google that PNG8 only supports binary (0 or 1) transparency. This explains the artefacts: alpha below 1 gets rounded to 0. Alfred 1 Quote Mac mini M1 A2348 | Windows 10 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. My posts focus on technical aspects and leave out most of social grease like „maybe“, „in my opinion“, „I might be wrong“ etc. just add copy/paste all these softeners from this signature to make reading more comfortable for you. Otherwise I’m a fine person which respects you and everyone and wants to be respected. Link to comment Share on other sites More sharing options...
AntiqueFlaneur Posted February 17, 2021 Author Share Posted February 17, 2021 36 minutes ago, Alfred said: I don’t see why it should matter, but did you have a particular reason for choosing the ‘PNG-8 (dithered)’ preset? That was the problem! Thanks! Alfred 1 Quote Link to comment Share on other sites More sharing options...
AntiqueFlaneur Posted February 17, 2021 Author Share Posted February 17, 2021 12 minutes ago, NotMyFault said: On iPad, i get the same artifacts when using PNG-8 (dithered)’ preset I found via google that PNG8 only supports binary (0 or 1) transparency. This explains the artefacts: alpha below 1 gets rounded to 0. That was it. Thanks! NotMyFault 1 Quote Link to comment Share on other sites More sharing options...
NotMyFault Posted February 17, 2021 Share Posted February 17, 2021 If someone needs to spot areas where alpha is not euqal to 1, this procedural text filter will show. This will help to to tune masks. firstdefence and Alfred 1 1 Quote Mac mini M1 A2348 | Windows 10 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. My posts focus on technical aspects and leave out most of social grease like „maybe“, „in my opinion“, „I might be wrong“ etc. just add copy/paste all these softeners from this signature to make reading more comfortable for you. Otherwise I’m a fine person which respects you and everyone and wants to be respected. Link to comment Share on other sites More sharing options...
Staff Patrick Connor Posted February 17, 2021 Staff Share Posted February 17, 2021 2 hours ago, NotMyFault said: alpha below 1 gets rounded to 0 I feel the export algorithm should do better than that and only alpha less that 50% would go out as transparent . Perhaps I am missing a subtlety but this feels like a bug @Pauls do you agree? Quote Patrick Connor Serif Europe Ltd Latest V2 releases on each platform Help make our apps better by joining our beta program! "There is nothing noble in being superior to your fellow man. True nobility lies in being superior to your previous self." W. L. Sheldon Link to comment Share on other sites More sharing options...
NotMyFault Posted February 18, 2021 Share Posted February 18, 2021 10 hours ago, Patrick Connor said: I feel the export algorithm should do better than that and only alpha less that 50% would go out as transparent . Perhaps I am missing a subtlety but this feels like a bug @Pauls do you agree? At least the current way is consistent with how mask are treated in layer stacks. There is no silver bullet, Affinity may make this threshold a parameter in the export dialogue. The real issue is somewhere else: Alpha values other than 0 and 1 will lead to unexpected results (when the function must round to 0 or 1), a selectable threshold will only vary the unexpected. I would suggest Affinity should present a warning when the alpha values would be rounded by the function (lost information) AND alpha values exist in the image that could get truncated so no warning if alpha is 0 /1 for all pixels Then, it would be great if the app would offer a kind of preview emphasizing the affected areas (similar to overexposed areas, or red selection overlay). Maybe the existing preview in the masking dialogue could be reused here. The preview should use only black for 0, white for 1, and red for everything in between. I could provide these as new version of the procedural texture filter. In the example of the original author of this thread, the mask needs some tweaking before it could be used for export, a different threshold would not help to fix the issue. kind regards, Timo Patrick Connor 1 Quote Mac mini M1 A2348 | Windows 10 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. My posts focus on technical aspects and leave out most of social grease like „maybe“, „in my opinion“, „I might be wrong“ etc. just add copy/paste all these softeners from this signature to make reading more comfortable for you. Otherwise I’m a fine person which respects you and everyone and wants to be respected. Link to comment Share on other sites More sharing options...
NotMyFault Posted February 18, 2021 Share Posted February 18, 2021 (edited) Following up the idea of "color overlay" to identify areas with alpha values in risk of clipping: With help of a procedutal texture live filter, you can re-color all "partial" alpha values in red. alpha = 0: black alpha = 1: white 0 < alpha < 1: red Edited February 18, 2021 by NotMyFault Typos Alfred, firstdefence and Patrick Connor 3 Quote Mac mini M1 A2348 | Windows 10 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. My posts focus on technical aspects and leave out most of social grease like „maybe“, „in my opinion“, „I might be wrong“ etc. just add copy/paste all these softeners from this signature to make reading more comfortable for you. Otherwise I’m a fine person which respects you and everyone and wants to be respected. Link to comment Share on other sites More sharing options...
Alfred Posted February 18, 2021 Share Posted February 18, 2021 1 hour ago, NotMyFault said: I would suggest Affinity should present a warning when the alpha values would be rounded by the function (lost information) AND alpha values exist in the image that could get truncated so no warning if alpha is 0 /1 for all pixels I suggest that the Affinity apps should present a warning whenever alpha transparency has been used but the chosen output format doesn’t support it. That would cover formats that don’t support transparency at all, as well as formats that only offer limited transparency options. NotMyFault 1 Quote Alfred Affinity Designer/Photo/Publisher 2 for Windows • Windows 10 Home/Pro Affinity Designer/Photo/Publisher 2 for iPad • iPadOS 17.5.1 (iPad 7th gen) Link to comment Share on other sites More sharing options...
Staff MEB Posted February 18, 2021 Staff Share Posted February 18, 2021 Hi @AntiqueFlaneur, Thanks for reporting this. I've logged the issue to be looked at. Quote A Guide to Learning Affinity Software Link to comment Share on other sites More sharing options...
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