Editing PDFs from “iReal b”

My main hobby outside of computers is singing jazz standards. I recently started using the nifty software “iReal b” for finding quick chord charts of standards. But I only have the iPad, and while it can see my home wifi network, I cannot print to my printer from the iPad since it is not “Airprint” compatible. *Grumble, murmur*

But I found a way to get the charts printed! From the “iReal b” program:
1. Select Share (touch the chart and then touch the icon in the lower right that looks like an arrow going out of a box),
2. then PDF,
3. then Email.

It will then email the chart to me as an attachment. However, the PDF has no whitespace margins (due to others asking the developer for the margins to be removed). This makes the chart bigger on the page, but unfortunately often clips the edges when printing. So what to do?

I use Linux (Ubuntu) as my primary computer operating system. Here is what I do to get the whole chart printed with nice margins. Please feel free to comment if you have a better approach. This is something I kludged together.

1. Convert the PDF to a PNG image file. From the command-line, type
convert chart.pdf chart.png
2. Edit the PNG file in Gimp, use the scale tool to scale the image down slightly while keeping the same canvas size (be sure to click the chain-link so that it scales in both directions at the same time). Use the move tool to center in the canvas.
3. This part is optional, but I like to type the song’s key (like Bb) in the upper right part of the chart, and maybe a tempo and starting note.
4. Export to the same PNG file name (overwrite).
5. Print the PNG to get a hard copy of your chart.

I wasn’t able to find any way to change margins of a PDF, so this is the work-around I developed. It seems to work very well.