commit 1daea33eec09c376b09739e204bee480f7bf4140
parent 5b4f601fc74a1ed607fb93fea7cabc4cc3a1f5ba
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Mon, 6 Mar 2023 22:44:29 +0100
Finished blog post
Diffstat:
1 file changed, 59 insertions(+), 20 deletions(-)
diff --git a/src/blog/2023-03-06-resize-pictures/resize-pictures.md b/src/blog/2023-03-06-resize-pictures/resize-pictures.md
@@ -12,39 +12,39 @@ $ du -h -d 1 sebastiano.tronto.net
225M sebastiano.tronto.net
```
-Stupid modern phones and their multi-megapixel cameras!
-I definitely do not want my minimalist blog to waste your bandwidth,
-I have to fix this. I could just go through all my pictures and resize
-them with something like [gimp](https://www.gimp.org/) - there are like
-10 of them. But that's boring. Let's do it with the command line instead.
+Stupid modern phones and their multi-megapixel cameras! I definitely
+do not want my minimalist blog to waste your bandwidth, I have to fix
+this. I could just go through all my pictures and resize them one by
+one with something like [gimp](https://www.gimp.org/) - there are like
+10 of them. But that's boring. Let's do it with the command line instead!
## ImageMagick
-The obvious question is: how do we even edit an image file
+The obvious question is: how do we even edit a picture
with the command line? Luckily, there is a tool for that:
-[ImageMagick](https://imagemagick.org/). This piece of software
-does a ton of things, and I do not use it very often. So I always
-need to look up what I want to do.
+[ImageMagick](https://imagemagick.org/). This piece of software can do a
+ton of things, and I do not use it very often, so I always need to look
+up what I want to do.
-One way to invoke ImageMagick is by calling the `convert` command,
-which can take a
+One way to invoke ImageMagick is by
+calling the `convert` command, which can take a
[`-resize`](https://imagemagick.org/script/command-line-options.php#resize)
option, followed by a
[`geometry`](https://imagemagick.org/script/command-line-processing.php#geometry)
-argument. After checking the online manual, I understood that the
-command I was looking for was:
+argument. After checking the online manual, I understood that the command
+I was looking for was:
```
$ convert picture.jpg -resize "750>" picture.jpg
```
which resizes `picture.jpg` by scaling it down to at most 750px width -
-keeping the ratio between width and height, and leaving it untouched if it
-is already smaller. The value 750 was chosen after a couple of attempts,
-it seems a good compromise between quality and size.
+preserving the ratio between width and height, and leaving the picture
+untouched if it is already smaller. The value 750 was chosen after a
+couple of attempts, it seems a good compromise between quality and size.
-And now I just have to do this for all the pictures. Of course, running
-the same command 10 times with a different argument is out of question.
+And now I just have to do this for all pictures. Of course, running the
+same command 10 times with a different argument is out of question.
## find(1)
@@ -58,7 +58,7 @@ running a command). The OpenBSD and GNU versions of find have some
differences, check your local manual page. The commands I use
here have been tested on the GNU version, but should be standard.
-To look for file and simply print their name, we can use `-name`:
+To look for files and simply print their name, we can use `-name`:
```
$ find src -name \*.jpg -or -name \*.png
@@ -75,12 +75,51 @@ src/blog/2023-02-25-job-control/jobs-diagram.png
src/blog/2022-12-30-blog-ready/pc-planner.jpg
```
+Notice how I had to escape the `*`: the strings `\*.jpg` and `\*.png`
+are part of the find command, we don't want the shell to expand them.
+
Now we can use `-exec` to run a command on each of these files,
using `{}` to refer to the file's name:
```
-find src \( -name \*.jpg -or -name \*.png \) -exec convert {} -resize "750>" {} \;
+$ find src \( -name \*.jpg -or -name \*.png \) -exec convert {} -resize "750>" {} \;
```
We get a couple of warnings about grayscale images, but whatever.
This seems to have worked.
+
+## The weight of history
+
+Let's see if things have improved:
+
+```
+$ du -h -d 1 sebastiano.tronto.net
+19M sebastiano.tronto.net/gemini
+19M sebastiano.tronto.net/http
+19M sebastiano.tronto.net/src
+102M sebastiano.tronto.net/.git
+158M sebastiano.tronto.net
+```
+
+That's... a bit disappointing. It looks like large pictures were not
+the only culprit - all the [slides for my math talks](../../research)
+are also quite heavy. Too bad, I am not going to change them now.
+Maybe in a follow-up post :-)
+
+Just like me with my old slides, git also wants to keep a memory
+of the past. After all, this is what version control system are
+supposed to do. If you are wondering why my website is a git
+repository, check out
+[this old blog post of mine](../2022-08-14-website). In the end,
+I don't really need the ability to revert my website to an older
+version, so I could just reset the repo from all the history
+at some point.
+
+## Conclusion
+
+ImageMagick is and find are both powerful tools. I am happy with looking
+up ImageMagick's syntax everytime, but I definitely want to become more
+proficient with find.
+
+This was not a hard task, but I have learned something new. I hope you
+did too :-)
