Use modified part of file path as new file name

Question

i want to import an image, modify it and then export the modified image.

Something like this:

img = Import["C:\\Images\\e4271-5.jpg"]

Some modifications happens.

StringTake[img,{21,27}]
cond=StringTake[img,7]
If[cond=="5",Export["C:\\Images\\e4271-55.jpg"],Export["C:\\Images\\e4271-11.jpg"]]

So i'll encounter two types of files, files with file names "name-1" and files with file names "name-5". I want mathematica to import the files, modify them and save them in the same folder with nearly the same name, only difference to the filename is that for the "name-1"-ones there is an extra "1" added to the file name. Resulting in "name-1" -> "name-11" and analoge "name-5" -> "name-55".

How do i do that? StringTake wont work because of the quotation marks with my string of interest.

Answer 1

If you are looking for a function which takes in a filepath and generates a filepath to a file with nearly the same name, but with a duplication of the final digit of the base name, then you can use String pattern recognition like this:

formatString = First@StringCases[#, x__ ~~ y_ ~~ ".jpg" :> x <> y <> y <> ".jpg"] &;
formatString@"C:\\Images\\e4271-5.jpg"

resulting in

"C:\Images\e4271-55.jpg"

Edit

I noticed that in version 10, the x_ and y_ show up in orange, which they didn't used to do. Normally this indicates an error, but the code executes fine. I swear there was a previous question which asked this, but I can't remember where it was. Why is this occurring?

Answer 2

You can use the various FileName functions to get the result you want. The following function will import all the files in the folder ../images, modifies them with the function DoThings and exports them with the original file name extended by the last character of the file name.

SetDirectory[".../images"];
Export[FileBaseName[#] <> StringTake[FileBaseName[#], -1] <> "." <> 
    FileExtension[#], DoThings[Import[#]]] & /@ FileNames[]