diff --git a/chapters/ch00-intro.tex b/chapters/ch00-intro.tex
index 4c74d78..20b89d9 100644
--- a/chapters/ch00-intro.tex
+++ b/chapters/ch00-intro.tex
@@ -10,4 +10,6 @@ What follows here is a compendium of Linux commands and various options that I h
 
 \paragraph{``How can I send you corrections or suggestions for future issues?''} My contact information is listed in the ``Impressum'' on page ii. 
 
-\paragraph{Filenames} To keep things simple, the input file will always be ``input'' in the example code, and likewise, the output file name will always be ``output''. If a file extension is not required, it will not be included. For example ``input.pdf'' means the input \textit{must} be a pdf file, whereas ``input'' means it can be any type of file the application can handle.
\ No newline at end of file
+\paragraph{Filenames} To keep things simple, the input file will always be ``input'' in the example code, and likewise, the output file name will always be ``output''. If a file extension is not required, it will not be included. For example ``input.pdf'' means the input \textit{must} be a pdf file, whereas ``input'' means it can be any type of file the application can handle.
+
+\paragraph{Why \LaTeX{}?} Because \LaTeX{} makes things consistent. It also (usually) makes things easier, but the few times it makes things harder are always learning opportunities and I walk away knowing something I didn't know before. It's fun figuring out how things work.
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diff --git a/chapters/ch01-images.tex b/chapters/ch01-images.tex
index 49c3f38..9c0c62a 100644
--- a/chapters/ch01-images.tex
+++ b/chapters/ch01-images.tex
@@ -32,7 +32,11 @@ Doubling the resolution along both axes will increase the file size by an approx
 
 \section{To Extract Images from a PDF File}
 
-\lettrine[findent=0mm]{T}{o} extract images from a pdf file, use the \texttt{pdfimages} command (also from the same package\index{poppler-utils} mentioned in \S \ref{poppler-utils} ). 
+\lettrine[findent=0mm]{T}{o} extract images from a pdf file, use the \texttt{pdfimages}\index{pdfimages} command (also from the same package\index{poppler-utils} mentioned in \S \ref{poppler-utils} ). As before, the \texttt{-f} flag denotes the first page you want to extract image files from and the \texttt{-l} flag denotes the last page to extract image files from. Omitting them both will extract images from all pages. 
+
+By default, images are saved as PBM (for monochrome images), PGM (for grayscale images), or PPM (for color images) files. Use the \texttt{-j} flag to save them as \texttt{jpeg} files or the \texttt{-J} flag to save them as \texttt{jpeg 2000} files. 
+
+The \texttt{-list} flag will send a list of image information to \texttt{stdout} including the image file name, the page number, the image dimensions and resolution, the color space type, and the color depth\index[concepts]{color depth}\index[concepts]{bits per component} (i.e., bits per component). If needed, this can redirected to a text file. To generate the list without generating any images, use the \texttt{-listonly} flag.
 
 
 \section{This is just a test}
diff --git a/ulc_001.tex b/ulc_001.tex
index f977b31..88929af 100644
--- a/ulc_001.tex
+++ b/ulc_001.tex
@@ -10,6 +10,7 @@
 \checkandfixthelayout % Required if you have altered settings for the memoir class
 % Make an index
 \makeindex[columns=3, title=Packages Mentioned, intoc]
+\makeindex[name=concepts, columns=3, title=Concepts, intoc]
 \begin{document}
 
 \pagenumbering{roman}
@@ -46,5 +47,6 @@
 \input{chapters/ch03-files}
 
 \printindex
+\printindex[concepts]
 
 \end{document}
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