The reason I asked if you had GIMP is because GIMP has a nice tool for blurring the background. Here’s how I blur bokehs in my pictures. As I said earlier, I learned a lot with trial-and-error, so this method might not be the best one, but at least it works for me! Everybody on Lenspiration, feel free to correct me! 🙂
Step 1: Open your picture with GIMP. Don’t forget to work on a copy of your original picture is case something goes wrong or you are not satisfied with the results!
Step 2: Enable the quick mask. It’s the tiny button with dotted lines located on the lower left corner. You’ll see your picture tinted pink. Don’t be afraid, everything is alright!
Then click on the eraser on your tool box (if it doesn’t shows up on your screen, you can open it pressing Ctrl+b). Once you have your eraser, erase all the pink from your picture except your flower (erase only your background). If you ever erase part of the flower, just press Ctrl+z and retry. You’ll want to use different sizes of erasers for doing a nice job. Just double-click your eraser icon and move the second slider to the right if you want a giant eraser and to the left if you want a tiny one. Also, you may click on the magnifing glass on the tool box to make your picture bigger and be more precise.
What you’ve done so far is to select a portion of the picture. There are other ways of doing this but the quick mask is probably the most precise. Once you have a part of your picture selected, you can use sharpening, selective coloring, etc., only to the portion you’ve selected.
Step 3 : On the top bar, click on ”Filters” (who is beside Tools). Then click on ”Blur”. Of the different types of blur, select the third one, ”Gaussian Blur”. Set your numbers so that the edges won’t be to hard-cut, and at the same time not too blurry so that the edges of your flower would loose sharpness. (Note : I use a French version of GIMP, so it is possible that the terms differ, if it’s not clear just ask and I will be glad to offer further explanation)
Step 4: Click again on the quick mask button. Your picture should lose the pink tint and have a dotted line around the flower. Go back to the ”Filters” on the top bar, click again on ”Blur” and again on ”Gaussian Blur”. Again, set your numbers so that it won’t look unrealistic, but at the same time enough to hide distracting elements.
Step 5: When you’ve finished editing your picture, press Ctrl+e. Hit ”Select the type of file” and select what type you want. I would recommend Jpeg, as it offers a greater compatibility.