[ncl-talk] high resolution png image

[Kyle Griffin]

Hi Micah,

This seems to me the type of result you would expect when using RasterFill
as a cnFillMode - the default should be cnAreaFill, which increases plot
time significantly, but might that be an issue?
Otherwise, I assume you're doing nothing else to mask the data, correct?
Sometimes masking data with a land mask can create similar blockiness,
although I am unaware (via inexperience) as to whether there is a
resolution dependence based on the plot size or native data resolution.


Kyle

----------------------------------------
Kyle S. Griffin
Department of Atmospheric and Oceanic Sciences
University of Wisconsin - Madison
Room 1421
1225 W Dayton St, Madison, WI 53706
Email: ksgriffin2 at wisc.edu

On Thu, Oct 30, 2014 at 11:37 AM, Micah Sklut <micahs2005 at gmail.com> wrote:

> Hi Kyle,
>
> Thanks for the reply.
>
> The dataset is of 0.05 degree resolution, so that certainly isn't the
> problem. I have attached an image of the same data, but limiting the
> min/max lat/lon to the US Mid Atlantic. In this image you will see much
> more detail. This is the type of detail I was hoping to achieve for the
> entire globe. I figured if I increased the resolution of the global png, it
> would create the desired effect, but as you can see from the global image I
> attached, this wasn't the case.
>
> Looking forward to hearing your thoughts.
> Thank you,
>
> Micah
>
>
>
> On Thu, Oct 30, 2014 at 12:26 PM, Kyle Griffin <ksgriffin2 at wisc.edu>
> wrote:
>
>> Micah,
>>
>> This looks more like a limitation of your dataset - SST data is not of
>> infinite resolution, and you're plotting far more pixels than would be data
>> points in even a 0.1˚ dataset! It looks like the internal pixels are the
>> same size as your coastlines, so I don't see an issue with NCL there. More
>> specifically, you are not actually plotting coastlines - they only plot if
>> you tell them to plot with a call to gsn_csm_map or another similar
>> plotting tool. If you're looking for high resolution coastlines, look at
>> the RANGS mapping capabilities in NCL. Beyond that, you can always plot
>> shapefiles as well.
>>
>> Yes, vector images are going to be extremely large and painful for even a
>> moderate resolution file over the full globe. When you say raster, are you
>> talking about it in the image sense (non-vector file) or in the cnFillMode
>> sense (RasterFill, AreaFill, etc.;
>> https://www.ncl.ucar.edu/Document/Graphics/Resources/cn.shtml#cnFillMode)?
>> Raster fill mode will make the data more blocky and reduce interpolation
>> between points, but the trade-off is a much faster plotting of the image
>> and works well for high-resolution datasets being plotted at relatively low
>> resolution/wide zoom.
>>
>>
>> Kyle
>>
>> ----------------------------------------
>> Kyle S. Griffin
>> Department of Atmospheric and Oceanic Sciences
>> University of Wisconsin - Madison
>> Room 1421
>> 1225 W Dayton St, Madison, WI 53706
>> Email: ksgriffin2 at wisc.edu
>>
>> On Thu, Oct 30, 2014 at 9:58 AM, Micah Sklut <micahs2005 at gmail.com>
>> wrote:
>>
>>> Hi,
>>>
>>> This is a follow up to my previous posts, in reference to searching for
>>> high resolution images that could be used as zooming/navigating (specific
>>> interest is with image tile layers).
>>>
>>> I figured if I created a png file with a high resolution, it would be
>>> able to capture the high detail, like with coastlines and so forth.
>>> I've attached an image with very high resolution (16384x16384), but as
>>> you can see, if you zoom the global image into the coastlines they are
>>> extremely blocky.
>>>
>>> Is is possible to capture high resolution features, such as coastlines
>>> in a global raster image with NCL?
>>>
>>> FYI, I tried the vector image route, but the file size was gigantic, so
>>> that didn't seem like a proper route.
>>>
>>> Thank you,
>>>
>>> --
>>> Micah Sklut
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>
>
>
> --
> Micah Sklut
>
>
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