I have mosaicked modis09 rasters that have areas of NoData
values displayed in black, I have used every option possible from raster con and set null conditions in raster calculator to setting the NoData
values to 0 in properties but the black spaces would not erase. Is there any other option available in ArcGIS 10.2 for solving this issue?
4 Answers
In ArcMap, NoData values default to transparent. However, you have the option to change them to something else. Are you sure they are truly NoData values and not something else? One way to test it to set the NoData values to a particular color (see screenshot). You can also use the ID button and click on the areas that are black to determine the actual value being used.
If you are willing and able to share the file, I will take a look, too. Sometimes it is easier to work with the actual data to determine what is amiss.
Good luck.
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Thank you, I have tried this method but it did not remove the unwanted areas, I have uploaded the image, if you could please take a look and give your opinion.– MashalNov 15, 2015 at 14:51
If there is nodata
then how can you remove them, there is nothing to remove? Even if you convert them to a zero value you just end up with the large blank areas coded as zero rather than nodata
(which is a legitimate value). If you have created a mosaic dataset as opposed to mosaicking a set of rasters into a new single raster dataset then you may have overlapping rasters where nodata
cells obscure underlying rasters and you end up with what you are showing. If this is the case you can set the draw order of the mosaic dataset by changing the property Default Mosaic Operator to MAX. Areas with overlap will show the maximum cell value from all overlapping cells.
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+1 MAX overlap rule is the way to go (i.e. assuming the NoData value is <=0).– Aaron ♦Nov 16, 2015 at 12:43
I think it is better to use raster calculator to remove this Nodata pixels first you should know the smallest pixel value say it will be Zero then you will use a 'Con' function as follows:
Con("B1" >= 0,"B1")
assuming that your band name is 'B1'
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Thank you, I will give this method another try and then inform about the result.– MashalNov 16, 2015 at 7:15
Looking at the image above, it appears that the images you mosaicked were "collared." Did you do the initial mosaic? If so, it may be easier to re-mosaic them in a manner to ensure there is no "collar." There's actually a couple of ways to do this, but specifying the appropriate method is often dependent on the source data.
On that note, did you download these data. If so, if you could send me a link, I will take a look and try to come up with the best way to do this.
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I downloaded the data from Laadsweb, here is the link ladsweb.nascom.nasa.gov/data/search.html.– MashalNov 18, 2015 at 4:05
nodata
values into zero? So zero does not exist as a value in the rest of the data? What do you intend to do when its converted to zero?