I am currently doing the following to decode base64 images in Javascript:

    var strImage = ;

    strImage = strToReplace.replace(data:image/jpeg;base64,, );

    strImage = strToReplace.replace(data:image/png;base64,, );

    strImage = strToReplace.replace(data:image/gif;base64,, );

    strImage = strToReplace.replace(data:image/bmp;base64,, );

As you can see above we are accepting the four most standard image types (jpeg, png, gif, bmp);

However, some of these images are very large and scanning through each one 4-5 times with replace seems a dreadful waste and terribly inefficient.

Is there a way I could reliably strip the data:image part of a base64 image string in a single pass?

Perhaps by detecting the first comma in the string?

Thanks in advance.