Latest Contributions by JohnFraser

Hi Cody, Thanks. Yes I posted about this a while ago. I stopped working on the mosaic when I found the edges of the images so poorly aligned and didn't know what to do about it. I'm a little more comfortable in arcmap now so I thought I'd try it again. By mosaic, I mean putting the ten images together to form a larger image The images are all referenced to the same basemap which at the moment is a 2011 edition by the US Dept of Agriculture, I believe. I reference the images one at a time with 30-50 points, then display all 10 images for the whole map. I don't recall using "Mosaic To New Raster" but I did explore a few tools when I first started this project. I just now made a Mosaic Dataset with "Create Mosaic Dataset" and will see how that goes with my 10 referenced images and their tie points. Next time I reference I will follow your suggestions about tie point placement. Yes, I use "Update Georeferencing", not "Rectify."  I'll write more as I work on this. Thanks so much. ... View more

Thanks for the suggestions. I will have Pro 1.4 soon.  I am having trouble installing the licenses since I replaced the HD recently. Regarding the dummy points at sea, how do you do that? Thanks again. ... View more

Regarding the above post: Please ignore it. I made yet another mosaic of the aerial photos, replacing the missing photo with another copy. It works and reopens OK after I close it. Thanks. john ... View more

Thanks Paul. I got the free month of Photoscan Pro as you suggested. Now to learn how to use it. Much appreciated. john ... View more

Problem: One of the ten images went missing from the mosaic when I opened up the file again after closing ArcMap. The missing image(#9) is at the very bottom left corner of the mosaic. Below are before and after images for comparison. It happens that the top image is cut off at the top but it's the bottom left corner of the images I'm referring to. When I examined the properties of image # 9, I noticed that the extent had changed so it's gone to another part of the world at: left -774681510.957742; right 765587077.215732; top 1002030686.2084 and bottom 992902249.935427. I reloaded the original links to image 9 several times but that didn't do anything to change the new extent numbers. Next I removed image 9 entirely and replaced it with a new copy of that image with a different name. After I added the links, the new image 9 was in its proper place in the mosaic. However, after I closed and reopened the file with new image 9, the NEW image was missing, just a before. New #9's properties indicate that it now has a different extent in some other part of the world. Can you help me figure out what is happening to change the image extent when I close and reopen the mosaic file? This extent change did happen once before with a previous mosaic. I never had to deal with that though because I made another mosaic. Thanks. ... View more

Got it. I now have the Historical Imagery toolset in My Toolbox. Big thanks. ... View more

Thanks. I didn't figure out a way to mosaic the ten images in Photoshop. I went ahead and georeferenced them once more onto a different image of the island with a 0.5m resolution that was taken in 2011. Two questions: 1. With regard to the contrast and brightness: Is there a way to batch process all ten images so they will come out with the same values? I can do that by hand but they are not going to match exactly and probably won't look good. 2. The residuals and RMS error on one of the images is particularly bad, RMS error being over 30 meters vs 10-20 on most other images. This image with the poor RMS is from the center of the island and stretches from coast to coast at sea level over central Mt Topachau which is about 450m high. Although the images are 2D, I'm wondering if the big difference in elevations in the image might account for the large residuals and RMS error. Thanks. Best regards, john ... View more

Hi Sephe and Rebecca, a belated thanks for your advice. We've had two typhoons this month here on Saipan. Power is intermittent and I haven't revisited the the blog long enough to respond. I appreciate the details you've laid out and will use them to get the new tools into my program which is 10.3.0.4322. Thanks again. ... View more

Thanks. I downloaded the Python toolset. which had a .pyt extension. I wasn't sure what to do with it so I dropped it into the Python window in ArcGis 10.3. It created a couple lines of ?instructions but nothing came of that. I then dropped the .pyt file into the Python GUI window (2.7.10 shell) in Python 2.7. That created a lot of what looked like ?instructions but I didn't know what to do with them. Could you tell me what to do with the toolset? Thanks and best regards. ... View more

Peter, That's great. Thanks so much. Best regards, john ... View more

Hi Peter, Thanks so much for your reply. Unfortunately I can't afford the fee for the User Conference unless you know of a scholarship or grant that I could apply for. l live on Saipan in the Western Pacific and it is also pretty expensive to get there. Hopefully there will be information online about the new feature and workflow after the conference. If you have any emailable material or url's I would appreciate you sending them. Thanks again. Best regards, john ... View more

Thanks Dan. See my reply to Sephe above. john ... View more

Thank you for your comments and information. The reference map is the esri World Image which esri makes available to anyone. World Image's spatial reference is WGS 1984 Web Mercator Auxiliary Sphere and I used that as the coordinate source for the images that were referenced to it. The purpose of the mosaic is to provide visitors, including researchers, to the CNMI Archives with a view of Saipan in 1945. I don't know what kind of accuracy and precision they will need. The archives curator says people ask for that sort of thing from time to time. I would at least like what you might call a nice qualitative map. The more accurate and precise, however, the better for researchers who might want to make measurements or take data from the map. For reference points, there are a fair amount of coastal features that seem to have remained stable since the aerial survey 70 years ago. In addition, there are some Japanese concrete buildings and fortifications which are still here. I've also used road intersections which in some cases are dead on but in others have moved.far enough that I've had to throw them out as references. To get an estimate of the photo scale, I measured across a large feature, Laulau Bay, on the scanned map and compared it a Google Earth measurement. The scale looks to be about 1:30,000. BTW, I recently got a hold of a government sponsored Lidar survey of Saipan and am considering including contour lines on the final product if that's possible. I am also wondering if I could make the Lidar my reference map. Thanks again. john ... View more

Hello all, The ten images which I mentioned in my first post have now been georeferenced using esri World Imagery. Attached are the ten images at 50% opacity 1. by themselves and 2. overlaying the World Imagery map. As you can see, there is a lot of overlap and features do not necessarily match up in the overlapping areas despite being georeferenced. I was wondering if it would be any better first mosaic the images in Photoshop before referencing them? One contributor mention orthorectifying the images to be part of this process. Can I save that step for later or possibly not do that at all if the mosaicked image alone seems suitable for my purpose? Does anyone have suggestions for how to proceed from here. Thanks. john ... View more