NGC Thumbnails

Sat Apr 15 06:25:09 UTC 2017

Yeah that would be cool.⁣

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On 15 Apr 2017, 3:27 PM, at 3:27 PM, "John S." <myxlflik at hotmail.com> wrote:
>Doesn't seem to be a lot of feedback right now.  I guess it could be
>because of the weekend?  Would you like to post a few of the bad
>examples and their NGC or IC numbers and I will see if I can do
>anything better with them?
>
>
>________________________________
>From: Kstars-devel <kstars-devel-bounces at kde.org> on behalf of Jasem
>Mutlaq <mutlaqja at ikarustech.com>
>Sent: Friday, April 14, 2017 10:34 AM
>To: KStars Development Mailing List
>Subject: Fwd: NGC Thumbnails
>
>Folks,
>
>We've been having discussions over generating NGC/IC thumbnails to be
>used in KStars detail dialog + observation planner. John, from INDI
>forums
>(http://indilib.org/forum/wish-list/2136-ngc-objects-thumbnails-for-object-planner.html?start=24#16162),
>spent a lot of time generating image file (200x200) for NGC and IC
>objects in KStars database. However, when inspecting the images, there
>were quite a few issues. Below is an email from John that discusses the
>limitation of the approach. I'd like to invite all the developers to
>chime in on their ideas on this topic.
>
>
>---------- Forwarded message ----------
>From: John S. <myxlflik at hotmail.com<mailto:myxlflik at hotmail.com>>
>Date: Fri, Apr 14, 2017 at 2:50 PM
>Subject: Re: NGC Thumbnails
>To: Jasem Mutlaq
><mutlaqja at ikarustech.com<mailto:mutlaqja at ikarustech.com>>
>
>
>
>Jasem,
>
>
>FYI - I have completed the IC pulls.  They can be gotten here. 
>https://1drv.ms/u/s!AnSnRFrNRtfXviLmrzlp6Ru6N7KZ
>
>[https://r1.res.office365.com/owa/prem/images/dc-generic_40.png]<https://1drv.ms/u/s!AnSnRFrNRtfXviLmrzlp6Ru6N7KZ>
>IC-Thumbnails.tar.gz<https://1drv.ms/u/s!AnSnRFrNRtfXviLmrzlp6Ru6N7KZ>
>Shared via OneDrive
>
>
>
>
>
>The images are straight from the NASA data.  The ones that are out of
>'out of focus' are likely the objects that are very small (less than
>two arc minutes in size).  There is an automated way to pull them and
>compile them in RGB.  The problem is that you either have to use all
>three channels from the lower resolution DSS survey or use 2 of the
>DSS2 channels (Red and Blue) and use the Green from DSS.  It's
>relatively easy to pull the objects, but it does take time.
>
>
>I made some choices on parameters when doing the pulls.
>
>200x200 pixels was the minimum thumbnail size.  1000x1000 was the
>maximum.
>
>2 arcminx2arcmin is the closest resolution.  This means all objects 2
>arcmin or smaller will be a 200x200 thumbnail scaled at 100
>pixels/arcmin
>
>I chose to scale this up linearly to 1000x1000 where a 10 arcmin object
>would be 1000x1000 and still be 100 pixels/arcmin
>
>For objects larger than this, they will be 1000x1000 where the scale
>will be the number of arcmin wide or tall the object is.
>
>
>As for the quality, I know a couple of the images are just bad because
>of the survey data.  I know there is room for improvement here, but we
>have 13000 object thumbnails that we didn't before.  [😊]
>
>
>As for how I did the pulls, I used excel to create a custom pull for
>each object using  the syntax needed by the skyview.jar file from the
>NASA SkyView virtual observatory site.  Please feel free to experiment
>with this yourself and see if you can come up with better results.  I
>will definitely look into this further for you, but it will likely be
>after this weekend.
>
>
>Here is an example pull for a black and white image:
>
>java -jar skyview.jar position='NGC 7000' survey=dss2r scaling=log
>smooth=7 pixels=1000 Size=1.66666666666667 quicklook=png nofits
>output=thumb-ngc7000
>
>This pulls NGC 7000 from the DSS2R survey at 1000x1000 pixels and
>1.66666 degrees (100 arcmin) of scale per side and downloads it as a
>png file.
>
>
>Here is an example pull for compiling RGB images:
>
>java -jar skyview.jar position='NGC 2024' survey=dss2r,dss,dss2b rgb
>scaling=log smooth=7 pixels=1000 Size=0.5 quicklook=png nofits
>output=thumb-ngc2024
>
>This pulls NGC 2024 using DSS2R for RED, DSS for GRN and DSS2B for BLU
>and combines them in RGB at 1000x1000 pixels and a scale of 30 arcmin
>per side.  This will download as a jpg and will have to be converted to
>png manually.
>
>
>Try out a few pulls and see what you think.  The skyview.jar file has
>to be in the directory you run the commands from.  I have no doubt we
>can do more work on this.  I suspect some of the objects will do color
>just fine, but I know I ran into significant color issues with some
>objects.  NGC 7000 we particularly nasty.  I suspect data from some of
>the other surveys was missing and the channels just didn't come out
>properly.  It's possible that some of the other surveys have the data,
>but I did not look into it yet.
>
>
>Let me know what you think and how you would like to proceed.
>
>
>John
>
>________________________________
>From: Jasem Mutlaq
><mutlaqja at ikarustech.com<mailto:mutlaqja at ikarustech.com>>
>Sent: Friday, April 14, 2017 5:38 AM
>To: myxlflik at hotmail.com<mailto:myxlflik at hotmail.com>
>Subject: NGC Thumbnails
>
>Hi John,
>
>I sent you invitation to Google hangouts chat as well in order to
>discuss anything quickly. So I looked at the NGC images and they're
>great. However, I noticed many of them are _severely_ out of focus or
>bad quality. Some of them are excellent quality (e.g.
>thumb-ngc2175.png) but your mileage varies.
>
>Also some images are too saturated (e.g. thumb-ngc45.png). I'm not sure
>what is causing this, but can you investigate and find out why? Also,
>how difficult would it be to generate color RGB images from DSS
>sources? Is there a way to automate this?
>
>I modified KStars so that it also displays the thumb images in the
>observation planner if the main image is missing. So things are looking
>good but we need good quality images before we publish them to end
>users.
>
>Great work!
>
>--
>Best Regards,
>Jasem Mutlaq
>
>
>
>
>--
>Best Regards,
>Jasem Mutlaq
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