[ncl-talk] high resolution png image

[Micah Sklut]

No, I"m not masking data. Yes, I am using RasterFill, and the resulting
image for the Mid Atlantic is great. But, when I expand to global, I lose
the high detail, no matter how much I increase the png resolution. So, just
wondering why I am losing detail with the global image, and if there is a
way around it.

On Thu, Oct 30, 2014 at 12:52 PM, Kyle Griffin <ksgriffin2 at wisc.edu> wrote:

> 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
>>>>
>>>> _______________________________________________
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>>>>
>>>>
>>>
>>
>>
>> --
>> Micah Sklut
>>
>>
>


-- 
Micah Sklut
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