So there are many questions similar to this, but none that I can find that answers this exact scenario:
After batch trimming a folder of images, how to then make the canvas square, whilst retaining the longest edge? I don't want to use -extent and make them all a fixed width.
Examples of desired output:
800x1200 becomes 1200x1200
1000x600 becomes 1000x1000
1625x1600 becomes 1625x1625 etc....
So for example, if -squared was a function, it would be something like:
mogrify -path squared/ -trim -background white -gravity center quality 75 -squared *.jpg
How to achieve this?
If on ImageMagick 7, you can do the following with -extent to get the max of w and h.
Input:
magick barn.jpg -background black -gravity center -extent "%[fx:max(w,h)]x%[fx:max(w,h)]" x.png
In ImageMagick 6, you can do something similar by using the viewport computations with -distort SRT, but you have to add the offset computations, since -gravity does not work with -distort SRT.
convert barn.jpg -set option:distort:viewport "%[fx:max(w,h)]x%[fx:max(w,h)]+%[fx:(w-max(w,h))/2]+%[fx:(h-max(w,h))/2]" -virtual-pixel black -filter point -distort SRT 0 +repage y.png
Related
Friends,
I need to -trim some images but keep the original canvas size. Works like this:
convert in.png -fuzz 10% -trim -background white -set page "%[fx:w]x%[fx:h]" +repage out.png
But how can I position the trimmed image part at it's original position? -gravitiy center is not an option as the to-be-trimmed part usually not at the canvas center.
Any ideas?
You should be able to -trim an image, then use -flatten to lay it back onto its original canvas. Try this command...
convert logo: -background none -trim -flatten trimmed.png
#GeeMack's answer is certainly simpler and more succinct, but if you need more flexibility for dinking around, another way is to get the image height and width and the trimbox in one invocation and use them in the next - maybe with adaptation.
So, starting with this image:
# Get image width and height and the trim-box
read geom trim < <(magick start.png -format "%G %#" info:)
# Make a new white canvas same size as original and trim new image onto it
magick -size $geom xc:white \( start.png -crop $trim \) -flatten result.png
I put an artificial yellow border around it so you can see the extent of it on SO's white background.
I want the size of the square should be equal to the largest side of the original photo
E.g.
Original: 500 x 400 => Output:500 x 500
Original: 400 x 600 => Output: 600 x 600
You can do that as follows for any given image in Imagemagick 7. To do multiple image, you would need to write a "for" loop, whose syntax depends upon your OS.
magick image.suffix -gravity center -background black -extent "%wx%h^" result.suffix
or
magick image.suffix -gravity center -background black -extent "%[fx:max(w,h)]x%[fx:max(w,h)]" result.suffix
Here is a better way to convert all images in a folder with either Imagemagick 6 or 7. I use -distort SRT's viewport to do the padding with a no-op warping (i.e. no rotation, scale or translation) in mogrify to process all images in the folder.
First create a new folder to hold your output images, if desired and use the -path option to mogrify. Specify a background color (in this case I use red).
For Imagemagick 7:
magick mogrify -path path_to/new_folder -virtual-pixel background -background red -set option:distort:viewport "%[fx:max(w,h)]x%[fx:max(w,h)]-%[fx:0.5*(max(w,h)-w)]-%[fx:0.5*(max(w,h)-h)]" +distort srt 0 *
For Imagemagick 6, remove "magick" before mogrify.
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
I'm after a very specific conversion result from Imagemagick, taking something like this:
And converting it into something like this (1140 pixels wide, 12px border around the top, left, and right of the original):
So far I'm using this code to convert it:
convert nike.jpg -colorspace RGB -density 72 -gravity west -background white -extent 1140x104 nike2.jpg
But I'm getting this very skewed result:
Any advice on how to get closer to my goal here? I guess I'm trying to chain Imagemagick commands here to reduce the size to 78px high, add a 12px border, then extend the background on the right to 1140px wide, and I'm not really sure how to chain commands in Imagemagick via Paperclip.
Solved perfectly:
convert nike.jpg -colorspace RGB -density 72 -resize 78 -gravity west -bordercolor white -border 12x12 -background white -extent 1140x104 nike3.jpg
Getting started with ImageMagic and trying to find a way to do this... If an image is less than 50 pixels tall or 50 pixels wide, I'd like to place it (un-scaled) in the horizontal/vertical center of a new 50x50 pixel canvas on top of a white background - and save that as the new image. Anyone know if this is possible with ImageMagick? Thanks!
I used -extent to do this:
convert input.jpg -gravity center -background white -extent 50x50 output.jpg
I wanted to do the same, except shrink the image to 70% inside. I used this:
convert input.png -resize 70%x70% -gravity center -background transparent -extent 72x72 output.png
Not exactly what was requested but hopefully it will help someone ;).
I have once used this code to place an image in the center of a new canvas with white background. hope this will help you
convert -background white -gravity center your_image.jpg -extent 50x50 new_image.jpg
See cutting and bordering for a huge number of examples. Here's one simple way you might do it:
convert input.png -bordercolor Black -border 5x5 output.png
Of course, you'll need to calculate the size of the border to add (if any) based on the dimensions of the input image. Are you using an ImageMagick API, or just the command line tools?
I tried this:
convert test.jpg -resize 100x100 -background black -gravity center -extent 100x100 output.png
You can use single composition to do this. So it would look something like this:
convert -size 50x50 xc:white null: ( my_image.png -coalesce ) -gravity Center -layers Composite -layers Optimize output.png
To modify the source image you need to use mogrify:
mogrify -gravity center -background white -extent 50x50 source.jpg
If an image is less than 50 pixels tall or 50 pixels wide
In my case, the images were much larger than the destination canvas, and weren't square. So I resize them proportionally to fit inside. Example:
convert in.png -resize 46x46 -background none -gravity center -extent 50x50 out.png
The 46x46 limit ensures a 2 pixel margin minimum. Note that the above does not distort the image, e.g. a rectangle does not become a square.
I used background none for a transparent background, but you can choose a solid color instead.