Exporting high resolution raster data to photoshop

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05-22-2018 05:31 AM
EdwardMarley
New Contributor

I have some very high-resolution DigitalGlobe satellite images, which I would like to crop and export to photoshop. It is crucial that I maintain the very high resolution of the raster dataset.

What is the best method to:

1. Crop a high-resolution satellite raster to an area of interest (AOI), yet maintain the very high resolution / quality.

2. Export this data, so it is viewable/editable in Photoshop yet maintains the very high resolution / quality.  

I was going to Clip to a polygon for the cropping. Will there be a loss of resolution using the Clip function? 

The data is currently in geotiff format.

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6 Replies
CodyBenkelman
Esri Regular Contributor

Ed

The "Clip" geoprocessing tool under data management inherently does this - it will ensure you don't resample the output.  (not the "Clip" tool for features). 

Just be sure to:

1) set your NoData value to 0 and

2) do NOT enable the "Maintain Clipping Extent" checkbox

Also note you'll have to create a feature (or enter numeric values for extent) to define the clip area 

Note the screenshot here is from Pro 2.1, and you didn't say which software you're using.

I'm concerned that perhaps there is more happening here - Is there a reason you don't simply use Photoshop to load the GeoTiffs?  Are you reprojecting the data?  Do you need to retain the georeferencing?  Are you extracting a subset of the spectral bands?  Are you mosaicking multiple images together?  (If yes to this last question, I'd recommend using a Mosaic Dataset to manage multiple images, then possibly the EXPORT functionality where you will have to specify the output resolution and also a "snap raster" to ensure the pixels are not resampled).

Hoping this is helpful

Cody 

EdwardMarley
New Contributor

Hi Cody. 

Thanks for the reply.

I'm using Arcmap 10.5. 

I'm using a .md/.til file which contains several geotiffs. I wish to use clip an Area of Interest, in which the time-series action will be occurring. As there is no overlay between the geotiffs, I will not be mosaicking them together. I am also not subsetting a set of spectral bands.  

The reason I'm using ArcGIS to process (clip and export) the raster is because Photoshop might struggle to process the many large geotiffs (each ~4-9GB each).

The reason Photoshop will be used to colour balance / stitch the time-series of the resulting cropped images is because this may be cumbersome in Arcmap. 

One more question.

When I load the satellite geotiff into ArcGIS, it is visible and in somewhat a natural colour. 

When I load in Photoshop, it is black and requires a lot of adjustments to be visible/ a natural colour. 

Is there anyway I can get photoshop to view the raster the same way ArcGIS does (i.e. with a natural colour balance and not as a black box that needs editing)


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CodyBenkelman
Esri Regular Contributor

It sounds like you have numerous images captured at different times and want to show a time series of an event?  ArcGIS (ArcMap and Pro) has extensive mosaicking and color balancing capabilities.

I'd encourage you look at this documentation What is a mosaic dataset?—Help | ArcGIS Desktop  and use a mosaic dataset to manage all of your images in one data structure, and note that you can activate a control for time here Setting the full time extent of the time slider—Help | ArcGIS Desktop 

If you have access to ArcGIS Pro, it can directly create movies or animated GIF files.  It's not clear that you'd need to use Photoshop.


Cody B.

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EdwardMarley
New Contributor

Unfortunately I only have access to Arcmap, not argis pro. 

Making the time-series isn't an issue, as my colleague have much experience using media software for this with images. 

The issue is exporting raster data from ArcGIS in a way that is easily visible. 

ArcGIS automatically applies a natural colour balance with percent clip or esri stretching, which does a good job. 

The issue is when I export this colour balanced data from ArcGIS and open it in photoshop or anything else, the tif is a black box that needs to be colour balance all over again.... 

Is there some way of mantaining the colour balance of an image in ArcGIS when exporting or replicating the colour balance from Arcmap? 

Here is an example:

One image shows the 16bit raster tif file in ArcGIS with a good natural colour balance, automatically applied in Arcmap.
The exact same image appearing as black tiff file in photoshop, which requires a lot of editing to contrast levels/curves beyond my knowledge. 

Regardless of what software I use to open the satellite tiff file, it always appears as a black file unless opened within arcmap 

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GuenterDoerffel
Esri Contributor

Marley,

in addition to Codys answers a comment on why you might not "see" anything but black initially in Photoshop (which I do not use or know at all):

If the DigitalGlobe product you use is stored in 16 bit, it still most likely only uses 11 or 12 bit to actually store the color values. In GIS this is quite common and as you experienced, handled well by the software. I would assume Photoshop does not really "know" how to handle digital Globe - it just takes the TIFF as any other 16bit tiff and there you go: It appears black. So if you want to do most of your workflow in Photoshop, you should probably consider to convert the files in one of several thinkable ways:

  • Stretch them to use the full 16 bit and write them out again to 16 bit (In ArcGIS you could use raster functions for that)
  • Stretch (would better call it de-stretch) them to 8 bit and save them as 8-bit TIFF - this would also considerably decrease the size of each file. As I saw somewhere that Photoshop can deal with YCbCr compressed files, you could use that and have them even smaller.

To get this done, you could use GitHub - Esri/OptimizeRasters: OptimizeRasters is a set of tools for converting raster data to optim... which will use standard GDAL routines to do so.

After conversion you can still follow the recommended Esri workflows and CLIP the data out, but as the format then might be better understood in Photoshop, that COULD do it.

But again - I dont know Photoshop ...

Regards
Guenter   

GuenterDoerffel
Esri Contributor

Sorry - Edward!

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