Black areas around the aerial photos after re-projecting

[D__SamuelRajasekhar]

Hello All,

I have historic aerial photos in TIFF format:
[ATTACH=CONFIG]24202[/ATTACH]
These display just fine (in State Plane)

The problem arises when I re-project them to UTM (NAD83) -> JP2 format (same with TIFF format too)
There is a dark area (some what resembling the extent).
[ATTACH=CONFIG]24203[/ATTACH]

When I set the display nodata value of 0 to NoColor, I get a tolerable image but still has some speckles in the collar area and holes inside (obviously 0 is a value).
[ATTACH=CONFIG]24204[/ATTACH]

During the re-projection process: I tried various methods - resampling, setting NoData, compression , etc. Evrytime it is the same result (dark around).
[ATTACH=CONFIG]24205[/ATTACH]

Am I missing something?
Is there a work-around?

Thanks

[RobertBorchert]

Double click on the raster in table of contents.

Click on the symbology tab.

There is a check box for Display Background Value:  Check that  to the right are places to enter values and next to that is a drop down box to select color.

Choose that and select no color.

What you are seeing is the full extent of the raster and by default it will give it a black color.

Hello All,

I have historic aerial photos in TIFF format:
[ATTACH=CONFIG]24202[/ATTACH]
These display just fine (in State Plane)

The problem arises when I re-project them to UTM (NAD83) -> JP2 format (same with TIFF format too)
There is a dark area (some what resembling the extent).
[ATTACH=CONFIG]24203[/ATTACH]

When I set the display nodata value of 0 to NoColor, I get a tolerable image but still has some speckles in the collar area and holes inside (obviously 0 is a value).
[ATTACH=CONFIG]24204[/ATTACH]

During the re-projection process: I tried various methods - resampling, setting NoData, compression , etc. Evrytime it is the same result (dark around).
[ATTACH=CONFIG]24205[/ATTACH]

Am I missing something?
Is there a work-around?

Thanks

[RobertBorchert]

Oh, and those speckles are simply imperfections in the raster.  There is enough color there so the show up as a color.

The image was probably scanned at the time it was made digital.


If you have a really good photo processor you may be able to open it there and cut the edges off.

It is just a rough edge.

Hello All,

I have historic aerial photos in TIFF format:
[ATTACH=CONFIG]24202[/ATTACH]
These display just fine (in State Plane)

The problem arises when I re-project them to UTM (NAD83) -> JP2 format (same with TIFF format too)
There is a dark area (some what resembling the extent).
[ATTACH=CONFIG]24203[/ATTACH]

When I set the display nodata value of 0 to NoColor, I get a tolerable image but still has some speckles in the collar area and holes inside (obviously 0 is a value).
[ATTACH=CONFIG]24204[/ATTACH]

During the re-projection process: I tried various methods - resampling, setting NoData, compression , etc. Evrytime it is the same result (dark around).
[ATTACH=CONFIG]24205[/ATTACH]

Am I missing something?
Is there a work-around?

Thanks

[Anonymous User]

Original User: sarajase

Thanks for the responses.

Yes, I tried it
the black collar has the value 0. So display background set to Zero.
[ATTACH=CONFIG]24208[/ATTACH]


The problem some of the areas inside (valid) also have zero values. So holes are showing up while the collar is removed (minimized).

[ATTACH=CONFIG]24209[/ATTACH]

Seems to be the problem repeatedly for different datasets.

[RobertBorchert]

cropping may be your only viable solution.

Those portions in the middle that are that way may be because the scan showed them as so dark they show up as background color.

IF you need the edges to be sharp and cropping does not work you can create a mask.  meaning make a great big polygon that is a hole in it that is a smaller than your raster and essentially just as a mask over the image.

A little cumbersome but it would cover it up.

Thanks for the responses.

Yes, I tried it
the black collar has the value 0. So display background set to Zero.
[ATTACH=CONFIG]24208[/ATTACH]


The problem some of the areas inside (valid) also have zero values. So holes are showing up while the collar is removed (minimized).

[ATTACH=CONFIG]24209[/ATTACH]

Seems to be the problem repeatedly for different datasets.

[RobertBorchert]

Perhaps you could get new copies.

Do you need the photos to be a specific year?

I know in my state we  have air photos dating back to 1991 readily available, and Older I suppose if I went digging for them.


Lastly you could instead place a black polygon behind the photo.  That would fill in those blank spots.

simply draw polygons in around the exposed area.  The way you did it with orange is great to see them. Then just put the polygon layer lower than the raster in table of contents.

[Anonymous User]

Original User: sarajase

Thanks for the detailed response.

Actually there are many (say half a million) or so frames.

I am using Python to process these in batches of say 250 to 500.

There seems to be interest about historic aerials as they captured the landscape in time.