blog: using imagemagick to crop soy faces

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+# Using imagemagick :imagemagick: to crop soy faces
+I'm pretty sure everyone knows that sometimes finding a good **PNG**  can be very hard, while there's always a bunch of the same **JPEG** images with the white background.
+After searching for 10 minutes, you decide to remove background yourself - using [GIMP](https://gimp.org) or something like `Photoshop` or `PAINT.NET` if you are on Windows. **Forget about it!** I'm gonna show you how you can use [imagemagick](https://imagemagick.org/) to automate basic tasks like removing background and cropping images.
+
+## Telegram sticker pack
+Every time I use Telegram stickers, I feel tired scrolling through many different packs trying to find the sticker I want. Sometimes, you just want them all to be in one place. That's why I created **Based Wojak** - a sticker pack which is automatically generated from random source images that I find on the internet.
+
+![based-wojak](https://user-images.githubusercontent.com/51545008/129426994-2a787714-772d-4010-b295-6ae00346bdbc.png)
+
+It doesn't matter if the image has a white background or wrong resolution, I just put it in the `src` folder and then magic :imagemagick: happens. For example, these are the source images used to generate the stickers above:
+
+![based-wojak-sources](https://user-images.githubusercontent.com/51545008/129427152-e01bc830-06e4-441a-9d8c-3dccbfb4d025.png)
+
+The collection itself is very small right now as you can see, but I plan to extend it as I need more stickers. Add this pack:
+
+https://t.me/addstickers/BasedWojak
+
+
+## Imagemagick
+Now, let's see how I've done that. Here's the GitHub :github: repo so you can follow:
+
+https://github.com/eug-vs/telegram-based-wojak
+
+You know, I love Makefiles. I use them everywhere (where they're appropriate), even this website is generated by a `Makefile`. Let's have a look at the `Makefile` for `telegram-based-wojak`:
+
+```Makefile
+# Makefile
+SOURCES=$(wildcard src/*)
+OUTPUTS=$(patsubst src/%.png, out/%.png, $(patsubst src/%.jpg, out/%.png, $(SOURCES)))
+
+SIZE=512x512
+FUZZ=50%
+
+VIEW_COMMAND=sxiv -t
+
+
+all: $(OUTPUTS)
+
+view: all
+	$(VIEW_COMMAND) out
+
+viewsrc:
+	$(VIEW_COMMAND) src
+
+out/%.png: src/%.*
+	@mkdir -p out
+	magick $< \
+		-fuzz $(FUZZ) -fill none \
+		-floodfill +0+0 white \
+		-floodfill "+%[fx:w-1]+0" white \
+		-trim +repage \
+		-resize $(SIZE) $@
+
+clean:
+	rm -rf out
+```
+
+On the first two lines I just create variables for input and output images. Then I define the `SIZE` - Telegram expects sticker's largest side to be `512px`. The value of `FUZZ` determines the sensitivity of removing the background - I use `50%`, but that's just something you can play with.
+
+Now let's have a closer look at the recipe for creating `out/%.png` from `src/%.*`. I use `magick` on the input file (denoted by `$<`), then pass a whole bunch of parameters to it, and finally provide the output file (`$@`). If you are confused by `$<` and `$@`, check out [Makefile cheatsheet](https://devhints.io/makefile).
+
+![imagemagick-logo](/public/emoji/imagemagick.png)
+
+
+### Removing the background
+To remove background, I use `-floodfill`, here's how [imagemagick wiki](https://imagemagick.org/script/command-line-options.php) describes it:
+> -floodfill {+-}x{+-}y color
+>
+> Floodfill the image with color at the specified offset.
+>
+> Flood fill starts from the given 'seed point' which is not gravity affected. Any color that matches within -fuzz color distance of the given color argument, connected to that 'seed point' will be replaced with the current -fill color.
+
+I use it two times: one in the top-left corner and one in the top-right. Top-left corner pixel obviously has a coordinate `+0+0`. To get the X coordinate of right-most pixel I have to use this expression: `+%[fx:w-1]`, Y coordinate stays at `0` of course. Since I already supplied `-fuzz` and `-fill none`, both operations will replace the white background with `none`, starting from two top corners of the image using the supplied fuzziness value.
+
+### Cropping the image
+After we removed background, most of the time we can trim a lot of extra space so that our image size corresponds to its content. Simple `-trim +repage` does the trick.
+
+### Adjusting the size
+All we have to do now is to make sure the sticker respects the size with `-resize` option. It will resize it in a way so it fits into `512x512` box without changing the aspect ratio (largest side will always be `512px`).
+
diff --git a/blog/index.md b/blog/index.md
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 ## 2021
 
+### August
+
+- [Using imagemagick :imagemagick: to crop soy faces](2021-08-14.md)
+
 ### July
 
 - [CircleCI :circleci: in daily life: how I improved Matrix stickerpicker](2021-07-15.md)
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