Cutting x pixels from an image - image-processing

Why this is creating many images instead of just two?
convert input-image.jpg -crop 28x +repage monet_vertical_%d.jpg
I want to get two images; 28 pixels from the base and another image with what's left.

convert $f -gravity South -crop 0x28+0+0 +repage label.jpg
convert $f -gravity South -chop 0x28 not-labeled.jpg

Related

Imagemagick create image and place image inside with max size

I have trimmed .pngs and need them placed on a canvas (3000x3000 px) BUT with a max size.
convert -size 3000x30000 xc:transparent test.png -gravity south -composite -size 2200x2200 result.png
The code I have now works, but the sizing of the image is off. My canvas is 3000x3000px as intended, but the image placed on the canvas doesn't have the correct size. It should have a max width/height of 2200px and if possible be scaled up, if they are to small in height.
This ImageMagick command will resize the input image to 2200 pixels on the longer side while maintaining its aspect, then create a 3000x3000 transparent canvas, then swap the input image and the canvas, and finish by compositing the resized input image onto the transparent canvas...
convert input.png -resize 2200x2200 \
-size 3000x3000 xc:none +swap -gravity south -composite result.png
For Windows change that continued line backslash "\" to a caret "^". For ImageMagick v7 use "magick" instead of "convert".
Unix syntax:
convert -size 3000x30000 xc:transparent \( test.png -resize 2200x2200 \) -gravity south -composite result.png
Windows syntax:
convert -size 3000x30000 xc:transparent ( test.png -resize 2200x2200 ) -gravity south -composite result.png
Why not use -extent?
convert input.jpg -resize 2200x2200 -background none -gravity south -extent 3000x3000 result.png

How to split an image with a grid and preserve transparency bounding box

I have some png images that I want to split it into parts, like by grid or size.
But each part should have the same bounding box (transparency) as original image.
Example:
Splitting image into 2 parts.
Original: 200 × 89
Output:
part_1.png, 200 × 89
part_2.png, 200 × 89
Can ImageMagick do this? Or any other app or method.
My actual goal is to split into 100+ slices images.
EDIT:
Another goal to have an indents for each slice. Say indent = 10px.
Example:
Input: 200 x 100
Output:
part_1.png, 200 x 100
part_2.png, 200 x 100
And just as example, to visually compare input and output: combined output images in Photoshop as layer added one onto another
200 x 100 :
Also this is showing input image added onto combined(so it's better to see what was cropped and how):
In ImageMagick, you can split an image into many parts with the -crop command. For your example above with two parts, you can do that with the following commands. ImageMagick will append -0, -1 ... to the output file names.
ImageMagick 6:
dim=`convert image.png -format "%wx%h" info:`
convert \( -size $dim xc:none \) null: \( image.png -crop 50x100% \) -layers composite result.png
ImageMagick 7:
magick \( image.png -set option:dim "%wx%h" -crop 50x100% \) null: \( -size "%[dim]" xc:none \) -reverse -layers composite result.png
The results are:
See
http://www.imagemagick.org/Usage/crop/#crop
http://www.imagemagick.org/Usage/crop/#crop_percent
http://www.imagemagick.org/Usage/crop/#crop_tile
http://www.imagemagick.org/Usage/crop/#crop_quad
http://www.imagemagick.org/Usage/crop/#crop_equal
http://www.imagemagick.org/script/command-line-options.php#layers
Note that -crop keeps the virtual canvas information if you do not add +repage afterwards. So to put the individual images back into their original placement, you have to composite them onto a transparent background the size of the input. That is done in one command using -layers composite using the null: separator.
Here is another way to add transparent areas between parts of a crop in ImageMagick. Crop the image into pieces, chop off the parts you want to remove, then pipe to montage to add the spacing back.
Input:
Here I make this into a 4x4 grid of images with 10 pixel spacing:
convert lena.png -crop 25%x25% +repage -gravity east -chop 10x0 -gravity south -chop 0x10 +repage miff:- | montage - -background none -tile 4x4 -geometry +5+5 result.png
To answer your new question, you can do that with a script loop. On a Unix-like platform, assuming your images do not have spaces, you can do the following:
cd path/to/current_folder
list=`ls *.png`
for img in $list; do
name=`convert $img -format "%t" info:`
dim=`convert $img -format "%wx%h" info:`
convert \( -size $dim xc:none \) null: \( $img -crop 50x100% \) -layers composite -scene 1 path/to/new_folder/${name}_%d.png
done
If you want leading 0s in the output, say 3, use path/to/new_folder/${name}_%03d.png.
Note that to start with 1 rather than 0, I have added -scene 1.
Sorry, I do not know how to script for Windows.
Please always provide your ImageMagick version and platform.
In ImageMagick, the best way to put transparent areas into your image is with a binary mask that is put into the alpha channel of your image.
convert input.png \( -size 200x89 xc:white -size 10x89 xc:black -gravity center -composite \) -alpha off -compose copy_opacity -composite result.png
You can add as many blank areas as you want by adding more white areas to the mask or by tiling out one region of black and one region of white to create the mask with regular spacing of black and white.
Edited to add this ImageMagick 6 example which splits the input image into 4 pieces, 25% of the original width and 100% of its height, then creates a transparent canvas for each piece the same dimensions of the input image, and locates the pieces at their original offsets on those canvases.
convert input.png -set option:distort:viewport %[w]x%[h] -crop 25x100% \
-virtual-pixel none -distort affine "0,0 %[fx:s.page.x],%[fx:s.page.y]" out%03d.png
The output file names will be numbered starting from zero like "out000.png", etc.
Original message...
Here's a simple command using ImageMagick 7 that can crop an image into any number of pieces, and output all the pieces at their original offsets on transparent backgrounds of the original input dimensions...
magick input.png -crop 100x1# -background none \
-extent "%[fx:s.page.width]x%[fx:s.page.height]-%[fx:s.page.x]-%[fx:s.page.y]" out%03d.png
That "-crop 100x1#" tells it to split the image into a grid 100 pieces wide by 1 piece high. You could just as well specify the crop sizes as percents or numbers of pixels.
Edited again to add:
This following command will split the input image into the individual pieces specified with the "-crop" operator, then shave 5 pixels from every side of each piece, then apply a 5 pixel transparent border to every side of each piece. It will still remember the original locations of the pieces within the input canvas, so the "-distort affine ..." can extend the canvases and place the pieces where they were in the input image.
convert input.png -set option:distort:viewport %[w]x%[h] \
-bordercolor none -background none -virtual-pixel none \
-crop 25x100% -shave 5x5 -border 5x5 \
-distort affine "0,0 %[fx:s.page.x],%[fx:s.page.y]" out%03d.png
To use this command with IM7 you need to change "convert" to "magick".
Given the changes of requirements provided by Kamikaze, here is one way to achieve the split with indent in ImageMagick, assuming I understand correctly.
dim=`convert image.png -format "%wx%h" info:`
convert \( -size $dim xc:none \) null: \( image.png -crop 50x100% -shave 5x5 \) -geometry +5+5 -layers composite result.png
To check, I flatten over a blue background:
convert result-0.png result-1.png -background blue -flatten result.png

Merge two Imagemagick convert commands

I'm trying to Create a thumbnail from GIF 1st command and then merge another image on top of it 2nd command.
1st command:-
convert -thumbnail 398x398 -auto-orient -quality 85 giphy.gif[0] output.jpg
2nd command:- convert -size 1920x1080 xc:none output.jpg -blur 5x4 -composite out1.png -gravity center -composite outfinal.png
I've tried using like this but didn't work out:
convert -thumbnail 398x398 -auto-orient -quality 85 giphy.gif[0] output.jpg | convert -size 398x398 xc:none output.jpg -blur 5x4 -composite out1.png -gravity center -composite outfinal.png
Image extracted from gif:-
2nd image:
Final output as merge two images :
Thank you:)
This is a pretty easy way to do it:
convert -gravity center background.jpg -blur 5x4 \
\( yinyang.png -resize 130x78\! \) \
-composite result.jpg
I put a spurious -resize 130x78\! in there so you can see where to do extra operations that only affect the little "yin yang" picture in the middle - you can obviously remove it.
Maybe I can explain the logic... the first line of the command deals with the background, the second line deals with the overlay. So, first, load up the background picture and make all the edits you want to it, i.e. blurring. Then start some "aside-processing" in parentheses which loads up the "yin yang" and applies some edits to that exclusively without affecting the background image. Then, when you are happy with the overlay, exit the parentheses and take the result of the "aside-processing" and overlay it on top of the background. It overlays into the centre because I set the gravity beforehand.
Hope that helps.
Added in response to your comment... if you want to do the extraction as well, just do that in the "aside-processing":
convert -gravity center \
giphy.gif[0] -thumbnail 398x398 -auto-orient -blur 5x4 \
\( yin yang -resize 300x100\! \) \
-composite result.jpg

ImageMagick chaining woes

I can't figure out how to properly chain commands in ImageMagick
Things that do what I expect in isolation :
Resize and then crop
$ convert input.jpg -resize '400x400>' -gravity center -crop 300x400+0+0 +repage output.jpg
Apply overlay
$ convert -composite input.jpg overlay.png output.jpg
Annotate
$ convert input.jpg -annotate +55+357 'The text I want' output.jpg
I've had limited success in combining these together for instance :
$ convert \( input.jpg -resize '400x400>' -gravity center -crop 300x400+0+0 +repage \) mask.png -composite output.jpg
Resizes the image and crops it, then applies my overlay. However regardless of what I try I can't then get the annotation to appear.
What I want to do is something like :
$ convert \( input.jpg -resize '400x400>' -gravity center -crop 300x400+0+0 +repage \) mask.png -composite \( -annotate +55+357 'The text I want' \) output.jpg
Thanks.
Answering my own question :
Adding -gravity NorthWest before the annotation solves the problem.
$ convert input.jpg -resize '400x400>' -gravity center -crop 300x400+0+0 +repage mask.png -composite -gravity NorthWest -annotate +55+357 'The text I want' output.jpg
I believe this effectively resets the 0,0 after the crop / resize so the annotation appears where it is expected to.
Note that you don't need the parenthesis either.
Credit to snibgo on the ImageMagick forum.

Crop 40/60 with ImageMagick

I know how to use -crop 50%x100% to split an image in half (50/50) but is there a way to crop into 40/60?
If I use
convert -crop 40%x100% in.jpg out.jpg
I end up getting:
out-0.jpg // 40%
out-1.jpg // 40%
out-2.jpg // remaining %
convert in.jpg -gravity west -crop 40%x100% +repage out1.jpg
convert in.jpg -gravity east -crop 60%x100% +repage out2.jpg
I'm sure there is a more complex way, but I would just do it in two commands.
You can do it in a single command like this:
convert in.jpg \
\( +clone -gravity east -crop 60x100% +repage +write east.jpg +delete \) \
-gravity west -crop 40x100% +repage west.jpg

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