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Color ramp for LBDA dataset makes most valid pixels transparent, the same as NODATA. #18

Open tmcphillips opened 6 years ago

tmcphillips commented 6 years ago

The values of the PMDI variable for the LBDA dataset is distributed around the value zero with a large fraction of values between -1 and 1 (see Jupyter notebook): image

Meanwhile, the color ramp for this variable colors pixels between -1 as 1 as transparent in the web app: image

Regions with NODATA also are transparent, so there is no way to distinguish many of the valid pixels from regions where there is no data. A color ramp that avoids this problem (same Jupyter notebook as above) yields the view below of the same year (2017) as rendered above:

image

This problem needs to be addressed before we release the LBDA data set to production.

tmcphillips commented 6 years ago

The GeoServer SLD REST service provides the Jet color ramp (the one used in the figure immediately above) as one of the predefined color ranges for raster data (the predefined ranges are RED, BLUE, GRAY, JET, RANDOM, and CUSTOM): http://docs.geoserver.org/stable/en/user/community/sldservice/index.html#classify-raster-data

The general definition of the Jet color ramp (as defined by MATLAB) can be found here... https://bugs.launchpad.net/inkscape/+bug/236508 ...according to which:

It is defined as a linear ramp between the following colours: "#00007F", "blue", "#007FFF", "cyan", "#7FFF7F", "yellow", "#FF7F00", "red", "#7F0000"

jterstriep commented 6 years ago

The Jet colormap is not considered particularly good for visualization purposes.

https://jakevdp.github.io/blog/2014/10/16/how-bad-is-your-colormap/

Additional color maps from matplotlib.

https://bids.github.io/colormap/

tmcphillips commented 6 years ago

Yeah, I found that blog post, too. I am only arguing that it is visible, which beats invisible, and intensely colored throughout which contrasts well with the less intense colors that base maps often use.

jterstriep commented 6 years ago

Mostly, I was just documenting it because that particular link has some other color ramp options.

tmcphillips commented 6 years ago

Is everyone happy with the current default color ramp for the PMDI variable? The colors corresponding to values between -3 and +3 are not very intense. Accepting the default 50% opacity it's still pretty hard to see where there is and isn't data:

image

Manually adjusting to 100% opacity it's a bit better:

image

bocinsky commented 6 years ago

Part of the issue might be the baseman we are using. How would people feel about switching to a grayscale basemap, like OpenStreetMap.BlackAndWhite? Some other options are at https://leaflet-extras.github.io/leaflet-providers/preview/ https://leaflet-extras.github.io/leaflet-providers/preview/.

http://{s}.tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png

On Jun 26, 2018, at 6:09 PM, Timothy McPhillips notifications@github.com wrote:

Is everyone happy with the current default color ramp for the PMDI variable? The colors corresponding to values between -3 and +3 are not very intense. Accepting the default 50% opacity it's still pretty hard to see where there is and isn't data:

https://user-images.githubusercontent.com/3218259/41945647-01e81008-7963-11e8-9d43-f274a1c8404f.png Manually adjusting to 100% opacity it's a bit better:

https://user-images.githubusercontent.com/3218259/41945684-39bc8892-7963-11e8-9599-8dd68107c825.png — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/openskope/Datasets/issues/18#issuecomment-400501229, or mute the thread https://github.com/notifications/unsubscribe-auth/AH8pM_JCiPE6VcBssRImVZWYahYZiixrks5uAs03gaJpZM4UqDdV.

bocinsky commented 6 years ago

Stamen.Toner is an even more neutral canvas.

On Jun 26, 2018, at 6:14 PM, R. Kyle Bocinsky bocinsky@gmail.com wrote:

Part of the issue might be the baseman we are using. How would people feel about switching to a grayscale basemap, like OpenStreetMap.BlackAndWhite? Some other options are at https://leaflet-extras.github.io/leaflet-providers/preview/ https://leaflet-extras.github.io/leaflet-providers/preview/.

http://{s}.tiles.wmflabs.org/bw-mapnik/ http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png

On Jun 26, 2018, at 6:09 PM, Timothy McPhillips <notifications@github.com mailto:notifications@github.com> wrote:

Is everyone happy with the current default color ramp for the PMDI variable? The colors corresponding to values between -3 and +3 are not very intense. Accepting the default 50% opacity it's still pretty hard to see where there is and isn't data:

https://user-images.githubusercontent.com/3218259/41945647-01e81008-7963-11e8-9d43-f274a1c8404f.png Manually adjusting to 100% opacity it's a bit better:

https://user-images.githubusercontent.com/3218259/41945684-39bc8892-7963-11e8-9599-8dd68107c825.png — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/openskope/Datasets/issues/18#issuecomment-400501229, or mute the thread https://github.com/notifications/unsubscribe-auth/AH8pM_JCiPE6VcBssRImVZWYahYZiixrks5uAs03gaJpZM4UqDdV.

kintigh commented 6 years ago

I think the base map we have now is a pretty good compromise between topography and landscape features and roads, land status, political entities etc. I think for trying to find your research area the B/W and stamen Toner ones would be impossible. We have as an issue about offering options and letting people choose (and I am happy for these to be options) , but by default I think we need the topography and land status, even if it makes the colors more difficult.

Keith

Keith W. Kintigh, Professor kintigh@asu.edumailto:kintigh@asu.edu ASU Directory Pagehttps://webapp4.asu.edu/directory/person/56433 ASU School of Human Evolution & Social Changehttp://shesc.asu.edu/ ASU Center for Archaeology & Societyhttps://shesc.asu.edu/centers/archaeology-and-society, Co-director Arizona State Universityhttp://asu.edu/, Box 872402, Tempe, AZ 85287-2402

Coalition for Archaeological Synthesis<http;/archsynth.org>, Interim Co-Chair Journal of Computer Applications in Archaeologyhttp://journal.caa-international.org/, Editorial Board

From: R. Kyle Bocinsky notifications@github.com Sent: Tuesday, June 26, 2018 6:18 PM To: openskope/Datasets Datasets@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [openskope/Datasets] Color ramp for LBDA dataset makes most valid pixels transparent, the same as NODATA. (#18)

Stamen.Toner is an even more neutral canvas.

On Jun 26, 2018, at 6:14 PM, R. Kyle Bocinsky bocinsky@gmail.com<mailto:bocinsky@gmail.com> wrote:

Part of the issue might be the baseman we are using. How would people feel about switching to a grayscale basemap, like OpenStreetMap.BlackAndWhite? Some other options are at https://leaflet-extras.github.io/leaflet-providers/preview/ https://leaflet-extras.github.io/leaflet-providers/preview/.

http://{s}.tiles.wmflabs.org/bw-mapnik/http://%7bs%7d.tiles.wmflabs.org/bw-mapnik/ http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png

On Jun 26, 2018, at 6:09 PM, Timothy McPhillips <notifications@github.com mailto:notifications@github.com<mailto:notifications@github.com%20%3cmailto:notifications@github.com>> wrote:

Is everyone happy with the current default color ramp for the PMDI variable? The colors corresponding to values between -3 and +3 are not very intense. Accepting the default 50% opacity it's still pretty hard to see where there is and isn't data:

https://user-images.githubusercontent.com/3218259/41945647-01e81008-7963-11e8-9d43-f274a1c8404f.png Manually adjusting to 100% opacity it's a bit better:

https://user-images.githubusercontent.com/3218259/41945684-39bc8892-7963-11e8-9599-8dd68107c825.png — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/openskope/Datasets/issues/18#issuecomment-400501229, or mute the thread https://github.com/notifications/unsubscribe-auth/AH8pM_JCiPE6VcBssRImVZWYahYZiixrks5uAs03gaJpZM4UqDdV.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHubhttps://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_openskope_Datasets_issues_18-23issuecomment-2D400502914&d=DwMFaQ&c=l45AxH-kUV29SRQusp9vYR0n1GycN4_2jInuKy6zbqQ&r=ur9s2KurOEwuMPidvsiKCoRQF9hp3xq6Pgyn4VShajU&m=QntFRoIu4MTJRWh_CtBYEcqE7uAdK4LnJmWitvtsbZk&s=RHyf-bXN9JMJQFyQ3IXbgb0NXW82qd3w5gNv3TMcK60&e=, or mute the threadhttps://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_notifications_unsubscribe-2Dauth_ALAoJZT1zaB5oxQd3gIrdxWjcuIILZsoks5uAs8lgaJpZM4UqDdV&d=DwMFaQ&c=l45AxH-kUV29SRQusp9vYR0n1GycN4_2jInuKy6zbqQ&r=ur9s2KurOEwuMPidvsiKCoRQF9hp3xq6Pgyn4VShajU&m=QntFRoIu4MTJRWh_CtBYEcqE7uAdK4LnJmWitvtsbZk&s=lGNnMcsCDKFmr6C1EqCuhZHO8jjeM0rHO60XrJKpvuE&e=.

bocinsky commented 6 years ago

That’s a good point, Keith.

On Jun 26, 2018, at 6:27 PM, Keith Kintigh notifications@github.com wrote:

I think the base map we have now is a pretty good compromise between topography and landscape features and roads, land status, political entities etc. I think for trying to find your research area the B/W and stamen Toner ones would be impossible. We have as an issue about offering options and letting people choose (and I am happy for these to be options) , but by default I think we need the topography and land status, even if it makes the colors more difficult.

Keith

Keith W. Kintigh, Professor kintigh@asu.edumailto:kintigh@asu.edu ASU Directory Pagehttps://webapp4.asu.edu/directory/person/56433 ASU School of Human Evolution & Social Changehttp://shesc.asu.edu/ ASU Center for Archaeology & Societyhttps://shesc.asu.edu/centers/archaeology-and-society, Co-director Arizona State Universityhttp://asu.edu/, Box 872402, Tempe, AZ 85287-2402

Coalition for Archaeological Synthesis<http;/archsynth.org>, Interim Co-Chair Journal of Computer Applications in Archaeologyhttp://journal.caa-international.org/, Editorial Board

From: R. Kyle Bocinsky notifications@github.com Sent: Tuesday, June 26, 2018 6:18 PM To: openskope/Datasets Datasets@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [openskope/Datasets] Color ramp for LBDA dataset makes most valid pixels transparent, the same as NODATA. (#18)

Stamen.Toner is an even more neutral canvas.

On Jun 26, 2018, at 6:14 PM, R. Kyle Bocinsky bocinsky@gmail.com<mailto:bocinsky@gmail.com> wrote:

Part of the issue might be the baseman we are using. How would people feel about switching to a grayscale basemap, like OpenStreetMap.BlackAndWhite? Some other options are at https://leaflet-extras.github.io/leaflet-providers/preview/ https://leaflet-extras.github.io/leaflet-providers/preview/.

http://{s}.tiles.wmflabs.org/bw-mapnik/http://%7bs%7d.tiles.wmflabs.org/bw-mapnik/ http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png

On Jun 26, 2018, at 6:09 PM, Timothy McPhillips <notifications@github.com mailto:notifications@github.com<mailto:notifications@github.com%20%3cmailto:notifications@github.com>> wrote:

Is everyone happy with the current default color ramp for the PMDI variable? The colors corresponding to values between -3 and +3 are not very intense. Accepting the default 50% opacity it's still pretty hard to see where there is and isn't data:

https://user-images.githubusercontent.com/3218259/41945647-01e81008-7963-11e8-9d43-f274a1c8404f.png Manually adjusting to 100% opacity it's a bit better:

https://user-images.githubusercontent.com/3218259/41945684-39bc8892-7963-11e8-9599-8dd68107c825.png — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/openskope/Datasets/issues/18#issuecomment-400501229, or mute the thread https://github.com/notifications/unsubscribe-auth/AH8pM_JCiPE6VcBssRImVZWYahYZiixrks5uAs03gaJpZM4UqDdV.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHubhttps://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_openskope_Datasets_issues_18-23issuecomment-2D400502914&d=DwMFaQ&c=l45AxH-kUV29SRQusp9vYR0n1GycN4_2jInuKy6zbqQ&r=ur9s2KurOEwuMPidvsiKCoRQF9hp3xq6Pgyn4VShajU&m=QntFRoIu4MTJRWh_CtBYEcqE7uAdK4LnJmWitvtsbZk&s=RHyf-bXN9JMJQFyQ3IXbgb0NXW82qd3w5gNv3TMcK60&e=, or mute the threadhttps://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_notifications_unsubscribe-2Dauth_ALAoJZT1zaB5oxQd3gIrdxWjcuIILZsoks5uAs8lgaJpZM4UqDdV&d=DwMFaQ&c=l45AxH-kUV29SRQusp9vYR0n1GycN4_2jInuKy6zbqQ&r=ur9s2KurOEwuMPidvsiKCoRQF9hp3xq6Pgyn4VShajU&m=QntFRoIu4MTJRWh_CtBYEcqE7uAdK4LnJmWitvtsbZk&s=lGNnMcsCDKFmr6C1EqCuhZHO8jjeM0rHO60XrJKpvuE&e=. — You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/openskope/Datasets/issues/18#issuecomment-400504432, or mute the thread https://github.com/notifications/unsubscribe-auth/AH8pM7SXJXq9_5dhee7_QUcghYs1M7Qhks5uAtFagaJpZM4UqDdV.