[Steve H]

Here are two screen shots in iCloud: https://share.icloud.com/photos/0eevKr98...EVRUJzqgvA

Please look at the first shot where the snipping tool has been used to place missing accidentals above the nudge tool. Now look at m. 151 in the second shot after save and exit.

There is a very clear shift downward that is erroneous. What is going on??

I also find that the enormously wide snipping box dotted lines are disconcerting and hard to work with. I also do not find documentation stating whether the snipping box includes the lines or is delimited by the insides of the lines. When they are so hugely wide this is of major consequence. I believe I have seen through experience that it is the outer borders that mark the area, but there are so many things going on here that just don't seem reasonable to me that I'm really at wits end.

[Zubersoft]

The snipping tool is not really designed to be used for precision editing of small symbols on the page. While it should still function for that purpose in some situations, that wasn't the original intent. In your example, it would be much better to just insert two stamps than trying to use the snipping tool for that purpose. The snipping tool will also copy the background behind anything you are copying, as it's copying the image pixels exactly, so it's not well suited for inserting into the middle of another section of the page like what you are trying to do. 

Regardless, I'll investigate what you are describing. It may have something to do with the conversion of coordinates between the zoomed in page and the original PDF page dimensions. The image you are inserting into the PDF has to be scaled down and moved to the correct position on the original PDF page dimensions. It looks to me less like the positioning is wrong and more like an issue with how the image is being scaled down. It's also complicated because there are some issues I've encountered with embedding images where the image size has to be divisible by 4 in order to avoid a crash with the PDF library I'm using, so I have to pad the image in those situations, which can throw off the accuracy a little bit, especially when dealing with a tiny image as in your example. This problem is unique to iOS - I did not encounter that problem on Android or Windows. I'll have to revisit this to see if they've made any fixes to prevent this from being needed.

Mike

[Steve H]

Thanks, Mike. You are at least able to help me understand your environment where you find inexplicable accommodations a particular OS may have chosen rather than to make their software just work the way anyone would expect it to. FYI, the approach I use to fix errata on scanned scores I figured out from using Paperport for years. For the most natural looking corrections I used bits of the score which automatically matched the original typesetting. I will see if I can use what's built into MobileSheets that you say is better suited for precision work.

[Steve H]

Mike, as I think about the advice I have listened to: Apple pencil is the way to go for precision tablet work, I'm really sad that you allow any breakdown at all of pixel-level accuracy. I fervently hope you find that the PDF library you use has a fix for you. I'm always willing to buy more hardware if I must, but I'm starting over if I have to find something that works so well on Android (or Windows?) but gives me what I am looking for in MobileSheets.

[Zubersoft]

Everything works well with pixel-level accuracy except for that one feature. Most users are not cutting and pasting individual symbols from a page repeatedly. As mentioned, it's much better to use the stamp tool for that purpose. What you are doing sounds like something that would be better accomplished in image editing software or a scoring application designed for that purpose. MobileSheets has some image editing capabilities obviously, but it is a sheet music management app first and foremost, not an image editing or scoring application. I'm not saying what you are asking for is unreasonable, but I don't think this is the highest priority for most users and given that I reported the issue well over a year ago to the PDF library company and did not get any help with the issue, I'm going to assume I'm not going to get much help with it.

Mike

[Zubersoft]

I do have some good news - I just tried writing out images pasted with the snipping tool without changing the image size to be divisible by 4, and I did not encounter any crashes or corruption. I will have to do more testing to ensure it's stable across a wide variety of PDFs, but this should fix the inaccuracies you've been encountering once this change is included in an update. I'm guessing the PDF library company must have fixed something at some point (they never publish release notes so I rarely know what they've changed).

Mike