Guidance on Use of Arcsinh Stretch

[jvickroy]

Hello.

I do not know how to use the Arcsinh stretch tool in Nebulosity 4.4.4. Scale factors <1 and >1 both produce pixel histograms with peaks shifted far to the right so the resultant images are severely bleached.

I would appreciate guidance on how to proceed.

Thanks,
/jim

[celstark]

All the tool does is, for each pixel, compute the arcsinh of that value – just a standard math function. For some images it may be a useful transformation while for others it may have bad effects. From: jvickroy ***@***.***> Date: Monday, January 29, 2024 at 6:42 PM To: celstark/OpenNebulosity ***@***.***> Cc: Subscribed ***@***.***> Subject: [celstark/OpenNebulosity] Guidance on Use of Arcsinh Stretch (Issue #5) Hello. I do not know how to use the Arcsinh stretch tool in Nebulosity 4.4.4. Scale factors <1 and >1 both produce pixel histograms with peaks shifted far to the right so the resultant images are severely bleached. I would appreciate guidance on how to proceed. Thanks, /jim — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/celstark/OpenNebulosity/issues/5__;!!CzAuKJ42GuquVTTmVmPViYEvSg!ORyvYT1S5YQWrHEBw4j3bbbZHmLRlNjc0ix-iI_p3PfoYY-qxfvXCpaSENuo5IYYNw21dfZaMmIw9nVKo_HxgjI$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ACJBVHQ2GQPIXB3O4QUV3HLYRBMZBAVCNFSM6AAAAABCQPF3DGVHI2DSMVQWIX3LMV43ASLTON2WKOZSGEYDMOBTG43TENQ__;!!CzAuKJ42GuquVTTmVmPViYEvSg!ORyvYT1S5YQWrHEBw4j3bbbZHmLRlNjc0ix-iI_p3PfoYY-qxfvXCpaSENuo5IYYNw21dfZaMmIw9nVKEVtEYqI$>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[jvickroy]

Thanks, Craig for taking the time to respond and thanks for Nebulosity. I will have to learn more about which types of images this stretch may be helpful. /jim

…

________________________________ From: Craig Stark ***@***.***> Sent: Tuesday, January 30, 2024 10:09 AM To: celstark/OpenNebulosity ***@***.***> Cc: jvickroy ***@***.***>; Author ***@***.***> Subject: Re: [celstark/OpenNebulosity] Guidance on Use of Arcsinh Stretch (Issue #5) All the tool does is, for each pixel, compute the arcsinh of that value – just a standard math function. For some images it may be a useful transformation while for others it may have bad effects. From: jvickroy ***@***.***> Date: Monday, January 29, 2024 at 6:42 PM To: celstark/OpenNebulosity ***@***.***> Cc: Subscribed ***@***.***> Subject: [celstark/OpenNebulosity] Guidance on Use of Arcsinh Stretch (Issue #5) Hello. I do not know how to use the Arcsinh stretch tool in Nebulosity 4.4.4. Scale factors <1 and >1 both produce pixel histograms with peaks shifted far to the right so the resultant images are severely bleached. I would appreciate guidance on how to proceed. Thanks, /jim — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/celstark/OpenNebulosity/issues/5__;!!CzAuKJ42GuquVTTmVmPViYEvSg!ORyvYT1S5YQWrHEBw4j3bbbZHmLRlNjc0ix-iI_p3PfoYY-qxfvXCpaSENuo5IYYNw21dfZaMmIw9nVKo_HxgjI$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ACJBVHQ2GQPIXB3O4QUV3HLYRBMZBAVCNFSM6AAAAABCQPF3DGVHI2DSMVQWIX3LMV43ASLTON2WKOZSGEYDMOBTG43TENQ__;!!CzAuKJ42GuquVTTmVmPViYEvSg!ORyvYT1S5YQWrHEBw4j3bbbZHmLRlNjc0ix-iI_p3PfoYY-qxfvXCpaSENuo5IYYNw21dfZaMmIw9nVKEVtEYqI$>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***> — Reply to this email directly, view it on GitHub<#5 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACIOVTV43P7H35NZM7J7B3TYRESLFAVCNFSM6AAAAABCQPF3DGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMJXGUYDQNZZGI>. You are receiving this because you authored the thread.Message ID: ***@***.***>