I have a set of images, and I can use the Imagemagick montage command on them to produce a montage image file with transparent background (let's call this fgimg). Now I have another existing image (let's call this bgimg) that I'd like to use (after some special processing with the convert command) as the background for fgimg, which can be achieved within the same convert command. At this point it seems trivial to avoid writing the temporary fgimg to disk, simply by piping the standard output of montage to the standard input of convert.
My problem is that the special processing I'm applying to bgimg will require some knowledge of the image properties of fgimg (e.g., resizing bgimg to have the same size as fgimg), which I don't know in advance. How can this information be retrieved and used in the convert command?
Note: I'm using Imagemagick version 6.9.7-4 on Linux.
I'll include some commands below to further illustrate the problem in detail.
The following command produces the montage image fgimg from a set of input images. The output is in the 'special' miff format (which seems best for temporary output to be worked on later), and has transparent background so that the actual background can be applied later. Most of the other options here are not important, but the point is that the output size (dimensions) cannot be determined in advance.
montage input_*.jpg -tile 5x -border 2 -geometry '200x200>+20+20' \
-gravity center -set label '%f\n%G' -background none -fill white \
-title 'Sample Title' miff:fgimg
Next, I have another input image bgimg.jpg. I want to perform some processing on it before using it as background to fgimg. The processing can be quite complex in general, but in this example, I want to:
resize bgimg.jpg to fit inside the dimensions of fgimg without any cropping;
apply a fade-to-black effect around the edges;
make it the same size as fgimg, with a black background;
combine this with fgimg to produce the final output.
Notice that I need the size of fgimg in two places. I can first extract this into a shell variable:
size=$(identify -format '%G' miff:fgimg)
Then I can do all the steps above in one convert command (note that $size is used twice):
convert "bgimg.jpg[$size]" -gravity center \
\( +clone -fill white -colorize 100% -bordercolor black \
-shave 20 -border 20 -blur 0x20 \) -compose multiply -composite \
-background black -compose copy -extent $size \
miff:fgimg -compose over -composite final_out.jpg
Now here is the problem: I want to avoid writing the temporary file fgimg to disk.
I could replace miff:fgimg with miff:- in both the montage and convert commands and then just pipe one to the other: montage ... | convert .... But how do I deal with the $size?
I tried to use file descriptors (miff:fd:3) but this does not seem to work, which is confirmed by the comments to this question.
Is there a way to do this (in Imagemagick v6) without creating a temporary file?
This example command uses ImageMagick v6 on a bash shell. Instead of "montage" it starts by using "convert" to create a "logo:", one of IM's built-in sample images, then pipes it out as a MIFF and into the "convert" command that follows. You can pipe the output of "montage" just as easily. And it uses another IM built-in image "rose:" as your "bgimg.jpg"...
convert logo: miff:- | convert - rose: \
+distort SRT "%[fx:t?min(u.w/v.w,u.h/v.h):1] 0" \
-shave 1 +repage -gravity center -bordercolor black \
\( -clone 1 -fill white -colorize 100 -shave 6 -border 6 \
-blur 0x6 -clone 1 -compose multiply -composite \) -delete 1 \
\( -clone 0 -alpha off -fill black -colorize 100 \
-clone 1 -compose over -composite \) -delete 1 \
+swap -composite final_out.jpg
That reads the piped image "-" and the background image "rose:".
Then it uses "+distort" with an FX expression to scale "rose:" to the maximum dimensions that still fit within the original piped input image. That operation adds a pixel all around so we use "-shave 1" to get rid of that.
Next inside parentheses it clones that re-scaled background image, makes an edge blur mask, and composites them to make the fade-to-black edge on the background image. Right after the parentheses it deletes the non-edged background image.
In the next parentheses it clones the input image, makes it black, clones the modified background image, and composites it centered over the black one. Again the non-extended background image is discarded after the parentheses with "-delete 1".
Finally the modified background and the input image are put in the proper order with "+swap" and composited for the final output. Run this command without the last "-composite" to see the two images that result from the prior parts of the command.
Both the main input image and background image can be any size, any dimensions, and any aspect ratio. This works for me on v6.8.9 on a bash shell. It should work on any ImageMagick newer. It should work on Windows by removing all the backslashes that escape parentheses and changing the continued-line backslashes "\" to carets "^".
EDITED TO ADD:
You can use that FX expression to find the scaling amount, save it as a variable, then isolate the background image inside parentheses and use that variable to do the scaling and shaving there. That way it only affects the background image. There may be a rounding error with that, but the main image, which determines the exact final output dimensions, will be unaffected. Note the difference in the first few lines of this command...
convert logo: miff:- | convert - rose: \
-set option:v1 "%[fx:min(u.w/v.w,u.h/v.h)]" \
\( -clone 1 +distort SRT "%[v1] 0" -shave 1 \) -delete 1 \
+repage -gravity center -bordercolor black \
\( -clone 1 -fill white -colorize 100 -shave 6 -border 6 \
-blur 0x6 -clone 1 -compose multiply -composite \) -delete 1 \
\( -clone 0 -alpha off -fill black -colorize 100 \
-clone 1 -compose over -composite \) -delete 1 \
+swap final_out.jpg
Related
How do I adjust the color ratio of a gradient?
I currently use the following to create my gradient.
convert -size 200x600 gradient:none-black output.png
Although at least one acceptable solution has been provided, here are a couple other ideas...
Example 1: This command creates a red-blue gradient of the finished dimensions, crops it into a top and bottom half, resizes them to 40 and 60 percent of the input height, and appends them back to make a single image. What started as the color at the exact vertical center is now at 40% down from the top with clean gradients going up and down from there.
convert -size 200x600 gradient:red-blue -crop 1x2# \
\( -clone 0 -resize 100x40% \) \( -clone 1 -resize 100x60% \) \
-delete 0,1 -append result.png
That splits the gradient image into a top and bottom half, then inside parentheses it resizes each to the required proportion. After that it deletes the 50/50 crops from before the parentheses, appends the two resized remaining images, and writes the output.
Example 2: This next example starts by creating the red-blue gradient in the final dimensions, then sets variables to hold the top color, the exact middle color, and the bottom color.
Then inside the first parentheses it clones and crops the image to 60% its original height. It uses "-sparse-color" to fill that with a gradient from "color1" to "color2".
Inside the second parentheses it clones and crops the image to 40% its original height, and using "-sparse-color" again it fills it with a gradient from "color2" to "color3".
After creating those two gradients, delete the original, append the other two together, and write the output.
convert -size 200x600 gradient:red-blue \
-set option:color1 "%[pixel:p{0,0}]" \
-set option:color2 "%[pixel:p{0,h/2}]" \
-set option:color3 "%[pixel:p{0,h}]" \
\( -clone 0 -extent 100x60% \
-sparse-color barycentric "0,0 %[color1] 0,%[h] %[color2]" \) \
\( -clone 0 -extent 100x40% \
-sparse-color barycentric "0,0 %[color2] 0,%[h] %[color3]" \) \
-delete 0 -append result.png
Maybe you want this, where you get to the half-red/half-blue colour just 20% of the way down the height of the image. It is done by creating two gradients of different lengths and putting them back-to-back:
midcolour="rgb(127,0,127)"
convert -size 100x20 gradient:red-"$midcolour" \
-size 100x80 gradient:"$midcolour"-blue \
-append result.png
Another way is to put 3 single pixels together in a row and then resize that up to what you want. I know you want the middle to be 40% red and 60% blue, but, for ease of viewing, I'll make it lime green:
convert -size 1x1 xc:red xc:lime xc:blue -append -resize 100x100\! result.png
You would change lime to something like "rgb(100,0,155)".
I am not quite sure I understand. But if you want to start with 90% transparent (10% opaque black) and end with black. You can do:
convert -size 200x600 gradient:"graya(0,0.1)-black" output.png
graya means gray with alpha. So graya(0,0.1) is gray(0) or black with 0.1 fraction opacity, so 90% transparent.
Perhaps this is what you want:
Normal 50-50:
convert -size 200x600 gradient:red-blue red_blue1.png
60-40:
rr=`convert xc: -format "%[fx:0.6*255]" info:`
bb=`convert xc: -format "%[fx:0.4*255]" info:`
convert -size 200x600 gradient:"rgb($rr,0,$bb)-rgb(0,0,255)" red_blue2.png
Or perhaps this is what you want:
bb=`convert xc: -format "%[fx:0.1*255]" info:`
convert -size 200x600 gradient:"rgb(255,0,$bb)-rgb(0,0,255)" red_blue3.png
I have an Imagemagick bash shell script called, multigradient, which may do what you want. It allows you to create gradients of many colors each with stops to set where they start. For example:
multigradient -w 200 -h 600 -s "blue 0 red 80" -d to-top result.png
The first color must start at 0, but the direction can be many options. Here I go from bottom to top with pure blue at the bottom and pure red starting at 80 up from the bottom going to the top
(See)
I already have the normalized vertices of my selected bounding box (e.g xmin: 0.68, ymin: 0.47, xmax: 0.94, ymax: 0.82) and I want to save this box in an other .jpg file. Furthermore, in the original image I want to make this highlighted box all white. Is this possible using Imagemagick?
Starting with this:
and knowing the top-left corner of the monument is at 400,10 and the bottom-right is at 500,200, you can extract the monument to a file with:
magick photo.jpg -crop 100x190+400+10 extract.jpg
and overpaint in white with:
magick photo.jpg -fill white -draw "rectangle 400,10 500,200" overpainted.jpg
Or, for extra fun, overpaint in semi-transparent white with:
magick photo.jpg -fill "rgba(255,255,255,0.5)" -draw "rectangle 400,10 500,200" overpainted.jpg
You can do both operations in one go with:
magick photo.jpg \( +clone -fill white -draw "rectangle 400,10 500,200" -write overpainted.jpg +delete \) -crop 100x190+400+10 extract.jpg
Using ImageMagick version 6, the command below will create two output images. (An example command for ImageMagick version 7 is further down in the reply.)
The first output image will be cropped from the input image using the bounding box starting at w*0.68xh*0.47 and ending at w*0.94xh*0.82.
The second output will be the input with a white section corresponding to the sub-image cropped out to make the first image.
convert input.png \
-set option:distort:viewport "%[fx:(w*0.94)-(w*0.68)]x%[fx:(h*0.82)-(h*0.47)]" \
\( +clone -distort affine "0,0 -%[fx:w*0.68],-%[fx:h*0.47]" \
-write result1.png -fill white -colorize 100 \) \
-set page "%[fx:u.w]x%[fx:u.h]+%[fx:t*(u.w*0.68)]+%[fx:t*(u.h*0.47)]" \
-flatten result2.png
That starts by reading the input image and calculating the viewport, the dimensions of the sub-image to crop, according to the bounding box dimensions you've provided.
Then inside the parentheses it creates a clone and does a "-distort affine" which, in effect, crops the image and locates it properly in that viewport. It writes that result to the first output image "result1.png". Then, still inside the parentheses, it fills that cropped piece with white.
After that it sets the paging geometry so that white piece can eventually be composited back into its original location over the input image.
It finishes by flattening the white piece onto the input image, and writes the second output image "result2.png".
The same thing can be done using ImageMagick version 7 with a slightly less complicated command...
magick input.png \
\( +clone \
-crop "%[fx:(w*0.94)-(w*0.68)]x%[fx:(h*0.82)-(h*0.47)]+%[fx:w*0.68]+%[fx:h*0.47]" \
-write result1.png -fill white -colorize 100 \) \
-flatten result2.png
That does the calculations directly in the "-crop" operation, and the paging geometry is saved in the cropped piece so it can be flattened back to its original position without resetting the geometry.
Those are in *nix syntax. To make it work in Windows change the continued line backslashes "\" to carets "^", and eliminate those backslashes that escape the parentheses "\(...\)".
Here is one other variation in ImageMagick 6. It crops the image and saves it and then deletes it. Then it use -region to write white into that bounding box.
This is Unix syntax. For Windows, remove \ from parenthesis and change end of line \ to ^.
Input:
convert img.jpg \
\( +clone -crop 100x190+400+10 +repage +write result1.jpg +delete \) \
-region 100x190+400+10 -fill white -colorize 100 +region result2.jpg
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
Follow up on “Diff” an image using ImageMagick
When you are working with forms (as opposed to images), the changes are very hard to see with this technique. I wanted to show some type of yellow highlight maybe 10-20 pixels "bigger" (padding) around the actual pixels that changed.
So instead of just this
Something more like this
It seems like I am just missing something here in the stack that can make this work.
convert '(' file1.png -flatten -grayscale Rec709Luminance ')' \
'(' file2.png -flatten -grayscale Rec709Luminance ')' \
... here ? ...
'(' -clone 0-1 -compose darken -composite ')' \
... or here ? ...
-channel RGB -combine diff.png
I can also run this as separate commands and does not need to be fast, most of this is going to be run offline.
I also tried studying the technique here (specifically how the thumbnail scaling gives you the effect I want as the pixels get expanded) but this code is using the library instead of the ImageMagick command line tools. Line 248 => "make the red as visible as possible"
https://github.com/vslavik/diff-pdf/blob/master/diff-pdf.cpp#L218
An example form is the standard W-9. I made 2 subtle changes
PART II .. moved the 2. left about 2 pixels
PART II .. on 4., moved word is to the right 2 pixels
and the compare pumps out this (changes in red that you can barely see)
Thank you for any help
You can use -morphology dilate in Imagemagick to increase the size of the red areas. For example, using your two forms:
convert JW0wZ.png 1nHWT.png -compose difference -composite -morphology dilate disk:10 +level-colors black,red result.gif
UPDATE:
If you want the background transparent, then try
convert JW0wZ.png 1nHWT.png -compose difference -composite -morphology dilate disk:10 +level-colors "black,red" -fuzz 20% -transparent black result.png
Or better
convert JW0wZ.png 1nHWT.png -compose difference -composite -morphology dilate disk:10 -alpha copy -background red -alpha shape result2.png
Update 2: Here is how to overlay a 50% yellow marking onto you two originals. Change the value as desired. I create a difference image and dilate the white. Then I create a 50% yellow image. Then I composite each of the originals with the yellow using the difference image as a mask. See https://www.imagemagick.org/Usage/compose/#compose
convert JW0wZ.png 1nHWT.png \
\( -clone 0,1 -compose difference -composite -morphology dilate disk:10 \) \
\( -clone 0 -fill yellow -colorize 100 -channel a -evaluate set 50% +channel \) \
\( -clone 0,3,2 -compose over -composite +write 1.png \) \
\( -clone 1,3,2 -compose over -composite +write 2.png \) \
null:
To view this, if on Unix and have X11 installed, you can do
animate -delay 20 -resize 50% 1.png 2.png
I want a combined command that can perform the following task in single execution. I searched the internet, but hardly found any tutorial that guide us to write any stack command. I can found single command for each operation, such as -composite, -blur, etc, and I know I can pipe the command as such
convert ... mpr:- | convert ... mpr:- | ... | convert ... png:-
However, I want a combined command that use \( ... \) and mpr:{label} since this will increase the performance as all operations are executed in single process (pipeline in shell can degrade the performance, and the process sequence is required to be in order).
The process sequence as such:
put flower.png on top of the frame.png -> mpr:framedFlower
put mpr:framedFlower on top of the background.png -> mpr:out2
blur the heart.png, right-gradient-transparent the smiley.png and put both image on top of mpr:out2 -> mpr:out3
annotate the mpr:out3 with "Hello world" (placement=bottom) -> png:-
I don't include the commands that I have tried because they are too messy and it will be an insult to those users who read it. I tried for many hours, but can't get it done. Please advise.
I haven't spent ages futzing with the exact coordinates as I am only using sample pictures, but this one-liner contains every technique you need to do what you are asking.
There is basically one line of code per element in the final image:
convert frame.png -resize 500x400\! \( flower.png -resize 400x300\! \) -gravity center -composite \
background.png +swap -gravity northwest -geometry +100+150 -composite \
\( heart.png -resize 200x200 -blur 0x8 \) -geometry +1200+250 -composite \
-gravity south -pointsize 72 -fill red -annotate +0+60 'Hello world' \
\( emoji.png -resize 250x250 -channel a -fx "u.a*(1-(i/w))" \) -gravity northwest -geometry +1200+500 -composite result.png
The first line reads in the picture frame and the flower and resizes them each independently because of the parentheses and then composites the flower into the frame.
The next line loads the background and then uses +swap to put it behind the framed picture from the previous line. It then sets -gravity to northwest as the origin for the ensuing -geometry before compositing the framed picture onto the background.
The next line loads the heart and resizes and blurs just the heart before compositing that onto the main picture at your specified position.
Next up is the annotation - the only interesting thing is that I set the -geometry to south which means that the offsets to -annotate are relative to the bottom centre of the background.
Finally, I load the emoji-thing and resize just it in parentheses before compositing over the main image. The only interesting thing is that I use -fx to alter the alpha channel (-channel a) and I multiply the existing transparency (u.a) by the fraction of the inverse of the distance we are across the image, namely (1-(i/w)).
Hope that is fairly clear!
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