I'm trying to merge every pair of images from a folder and combine that result into a PDF file with imagemagick and parallelize the process with GNU Parallel.
parallel -N2 convert \( {1} -rotate 30 \) {2} +append miff:- ::: *jpeg | convert - out.pdf
The problem is that I need to rotate the first argument and an error occurs.
Error: /bin/sh: -c: line 0: syntax error near unexpected token `01.jpeg'
/bin/sh: -c: line 0: `convert ( 01.jpeg -rotate 30 ) 02.jpeg +append miff:-'
...
How can I process one of the arguments GNU parallel is receiving?
First, you better use parallel -k else the output will be in the wrong order.
Second, you don't need parentheses to ensure your -rotate only applies to the first image because you haven't loaded a second at that point.
So, you are looking at:
parallel -k -N2 convert {1} -rotate 30 {2} +append miff:- ::: *jpeg | convert - out.pdf
or maybe:
parallel -k -N2 'convert {1} -rotate 30 {2} +append miff:-' ::: *jpeg | convert - out.pdf
In answer to your question, ImageMagick will apply operators (like -rotate) to all images in the loaded stack. So:
convert im1.png im2.png -rotate ...
will rotate both images. Whereas:
convert im1.png -rotate 90 im2.png ...
will only rotate the first image. If you want to only rotate the second, you have 2 choices, either put the second in parentheses so the -rotate only applies to it:
convert im1.png \( im2.png -rotate 90 \) ...
or, load the second image first and rotate it, then load the first and swap the order:
convert im2.png -rotate 90 im1.png +swap ...
Related
i have a folder of images with names foo<bar>.png where <bar> ranges from 0 to 100.
When i create a gif of these images with
convert -dispose previous -delay 10 -resize 25% -loop 0 *.png myimage.gif
it creates a gif with images in order like 0,1,2,3...
Is there a command to select images in random order?
If your PNG images are all the same dimensions, and if the number of images can be evenly divided into a grid, like 72 images would make a grid of 8 x 9 images, and if your images are small enough to read them all into a single ImageMagick command, here is a command that will randomize the order of a group of 72 input images...
convert *.png -virtual-pixel tile +append -crop 9x1# -append +repage ^
-crop 1x9# -distort affine "0,0 %[fx:floor(rand()*8)*(w/8)],0" -append +repage ^
-crop 8x1# -distort affine "0,0 0,%[fx:floor(rand()*9)*(h/9)]" +append +repage ^
-crop 8x9# +repage -set delay 10 -loop 0 image.gif
It basically makes a grid, randomly rolls all the rows, then randomly rolls all the columns. The shuffle scatters the images pretty well, but if you want a deeper shuffle, copy and paste those two "-crop ... -distort" lines, and add them below the first two...
convert *.png -virtual-pixel tile +append -crop 9x1# -append +repage ^
-crop 1x9# -distort affine "0,0 %[fx:floor(rand()*8)*(w/8)],0" -append +repage ^
-crop 8x1# -distort affine "0,0 0,%[fx:floor(rand()*9)*(h/9)]" +append +repage ^
-crop 1x9# -distort affine "0,0 %[fx:floor(rand()*8)*(w/8)],0" -append +repage ^
-crop 8x1# -distort affine "0,0 0,%[fx:floor(rand()*9)*(h/9)]" +append +repage ^
-crop 8x9# +repage -set delay 10 -loop 0 image.gif
Carefully replace the "8"s and "9"s with the width and height of the grid that holds the number of images you're using. I use it in a script that shuffles a deck of playing card images, 13 rows and 4 columns.
This uses ImageMagick v6 in Windows CMD syntax. In a BAT script double all the percent signs "%%". It would probably work on a *nix OS by changing all the continued-line carets "^" to backslashes "\". For ImageMagick v7 use "magick" instead of "convert".
I can tell you 2/3 of the answer on Windows, and hopefully some other kind soul can add the rest for you. Nobody said answers have to be complete.
Create a text file containing the names of the PNGs you want to animate. I believe that is:
DIR /B *.png > filelist.txt
Shuffle the lines in that file. I don't know how to do that in Windows. In Linux and macOS it is shuf. Here's a little Python equivalent:
python -c "import random, sys; lines = open(sys.argv[1]).readlines(); random.shuffle(lines); print ''.join(lines)," filelist.txt > shuffled.txt
Pass that file to ImageMagick like this:
convert -loop 0 -delay 80 #filelist.txt animation.gif
If you get that working, you can avoid the need for a temporary file by using this syntax:
DIR /B *.png | SHUFFLELINES | convert -loop 0 -delay 80 #- animation.gif
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
I'm trying to use this dataset to do Exposure Meging (Fusion) in Python. Each image in the dataset has an OpenEXR file that can be downloaded (i don't have much experience with this file format).
I want to extract different samples (jpg or png) from the OpenEXR file with different exposures .
I managed to do that in Darktable :
Open the OpenEXR file (image)
Change the Exposure
Save as jpg
redo for each exposure value (-3EV, -2EV, -1EV, 0EV, 1EV, 2EV, 3EV).
The problem : I have 100 images and i want to automate this process. any idea on how to do that ?
Thank you in advance
Since each increment of EV ("Exposure Value") corresponds to doubling the exposure, and EXR files are in linear light (not gamma-encoded), you would expect that you can double the pixel values in an EXR file to add 1EV and halve them to do -1EV...
So, I downloaded the Luxo EXR file from here. Then I went into Photoshop and clicked:
Image -> Mode -> 8-bits/channel
and selected Method = Exposure and Gamma and set exposure=+1 and saved the resulting file as a JPEG with +1 in its name. I repeated that for EV-3, EV-2, EV+0, EV+1, EV+2, EV+3.
I then looked at the resulting files with ImageMagick using commands like the following in the Terminal to examine the mean value of the combined RGB image:
magick identify -verbose image-EV+2.jpg
I then went about producing those same mean values, and found that the following works:
# To increase 1 EV
magick input.exr -evaluate multiply 2 result.jpg
# To increase 2 EV
magick input.exr -evaluate multiply 4 result.jpg
# To increase 3 EV
magick input.exr -evaluate multiply 8 result.jpg
And so on...
So, I wrote a bash script to do that as follows, which you could save in your HOME directory as adjust.sh:
#!/bin/bash
# Default file, if none specified
file=${1:-/Users/mark/Desktop/LuxoDoubleChecker.exr}
# Default EV of +1, if none specified
EV=${2:-1}
# Strip extension
base="${file%.*}"
# Apply given EV to file and save with new name
new="${base}EV${EV}.jpg"
echo "Applying EV $EV to $file, saving as $new"
magick "$file" -evaluate multiply $(bc -l <<< "2^$EV") "$new"
Then, just necessary once, make it executable:
chmod +x $HOME/adjust.sh
And then you run it like this to add +3EV to SomeImage.exr:
~/adjust.sh SomeImage.exr 3
Sample Output
Applying EV 3 to SomeImage.exr, saving as SomeImageEV3.jpg
Alternatively, if you save this script as allEVs.sh, it will load the specified image just once and generate all 7 exposures in one go without re-reading the input EXR file 7 times:
#!/bin/bash
# Default file, if none specified
file=${1:-/Users/mark/Desktop/LuxoDoubleChecker.exr}
# Strip extension to get base without extension
base="${file%.*}"
magick "$file" \
\( +clone -evaluate multiply 0.125 -write "${base}EV-3.jpg" +delete \) \
\( +clone -evaluate multiply 0.25 -write "${base}EV-2.jpg" +delete \) \
\( +clone -evaluate multiply 0.5 -write "${base}EV-1.jpg" +delete \) \
\( +clone -evaluate multiply 1 -write "${base}EV-0.jpg" +delete \) \
\( +clone -evaluate multiply 2 -write "${base}EV+1.jpg" +delete \) \
\( +clone -evaluate multiply 4 -write "${base}EV+2.jpg" +delete \) \
-evaluate multiply 8 "${base}EV+3.jpg"
Please check carefully that this works correctly for you before basing a lifetime's analysis on it...
Keywords: Image processing, HDR, High Dynamic Range, EXR, EV, Exposure Value, f-stop, stop, stops, exposure, increase, decrease, tone map, ImageMagick.
Given an animated gif over a solid background color
I'd like to trim away the padding. Concretely, I'd like to crop the image to the maximum extent of the foreground object over all frames:
I can't seem to find the right combination of -alpha, -background to achieve this with a single convert command. For example, if I issue
convert -dispose 2 input.gif -trim -layers TrimBounds fail.gif
I get random "background" colors for frames whose individual trimmed extents are smaller than the maximum extent over all frames:
I can achieve the correct output with a long string of commands:
convert input.gif -trim -layers TrimBounds out-%03d.miff
mogrify -background "rgb(20%,30%,80%)" -layers flatten out-*.miff
convert out-*.miff output.gif
rm out-*.miff
This is slow, writes a bunch of temporary files, and requires me to know the background color ("rgb(20%,30%,80%)") explicitly.
Is there a simpler way to trim an animated gif?
This related question considers explicit cropping rather than automatic trimming.
Finally, this seems to work in ImageMagick with one line to get the background color and one line of processing. No temp files are needed.
bgcolor=`convert input.gif[0] -format "%[pixel:u.p{0,0}]" info:`
convert -dispose previous -delay 10 -background "$bgcolor" input.gif -trim -layers TrimBounds -coalesce -layers optimize -loop 0 output.gif
You can accomplish this sort of trimming using IM's "-distort" with a defined viewport.
convert oHBWq.gif -coalesce +repage -background none \
\( -clone 0--1 -trim -flatten -trim \) \
-set option:distort:viewport %[fx:u[-1].w]x%[fx:u[-1].h]+%[fx:u[-1].page.x]+%[fx:u[-1].page.y] \
-delete -1 -distort SRT 0 +repage output.gif
That clones the input frames, trims them individually, and flattens them keeping their original alignment. Then it trims that flattened one again to get rid of the excess transparent background. The result will be the right size and have the correct page offsets for the finished images. You don't have to know the background color.
Now you can easily get those dimensions and offsets into a distort viewport setting and do a no-op distort. Delete the cloned flattened one that was used to get the measurements, "+repage" the rest, and finish with whatever other GIF settings you need.
This is an interesting question. At the moment, I do not see how to improve it so that extra file(s) are not needed. But I will consider it further. But I can clean your code up a bit and make it easier for you and make the output.gif look correct.
bgcolor=`convert oHBWq.gif[0] -format "%[pixel:u.p{0,0}]" info:`
convert oHBWq.gif -trim -layers TrimBounds out-%03d.miff
mogrify -background "$bgcolor" -layers flatten out-*.miff
convert -dispose previous -delay 10 out-*.miff -loop 0 output.gif
rm out-*.miff
This does the same thing as above, but only requires saving 1 multi-frame miff file. The subshell loop processing does similar to your mogrify.
bgcolor=`convert oHBWq.gif[0] -format "%[pixel:u.p{0,0}]" info:`
num=`convert oHBWq.gif -format "%n\n" info: | head -n 1`
convert oHBWq.gif -trim -layers TrimBounds tmp.miff
(for ((i=0; i<num; i++)); do
convert tmp.miff[$i] -background "$bgcolor" -layers flatten miff:-
done ) |\
convert -dispose previous -delay 10 - -loop 0 output2.gif
rm tmp.miff
This also works without having to save any temp files, but is has to repeat the -trim -layers trim bounds for each loop iteration.
bgcolor=`convert oHBWq.gif[0] -format "%[pixel:u.p{0,0}]" info:`
num=`convert oHBWq.gif -format "%n\n" info: | head -n 1`
echo "num=$num"
(for ((i=0; i<num; i++)); do
convert oHBWq.gif -trim -layers TrimBounds miff:- |\
convert -[$i] -background "$bgcolor" -layers flatten miff:-
done ) |\
convert -dispose previous -delay 10 - -loop 0 output3.gif
This is close but for one frame:
bgcolor=`convert oHBWq.gif[0] -format "%[pixel:u.p{0,0}]" info:`
convert -dispose previous -delay 10 oHBWq.gif -trim -layers TrimBounds -background "$bgcolor" -layers optimize -loop 0 output5.gif
I have 200 copies of this page(15 * 10 matrix) and i have to write all the numbers from 0 - 9 in each corresponding cell and then extract those digits digitally in a seperate image of (32*32 pixels) for each digit, after scanning each page once. How can i achieve this? This is required for my research purpose. I am a CS student so i can code too.
Update:
For mark : Here is one of the scanned image
This is for some local language ( 0 - 9) ..
Update 2:
The commands for the previous image are working fine but on new images,something is getting wrong(some kind of offsets)..
I am attaching the image below
What changes do u suggest ?
Updated Answer
I have taken your feedback and improved the algorithm to the following bash script now...
#!/bin/bash
################################################################################
# dice
#
# Trim borders off an image (twice) and then dice into 10x15 cells.
#
# Usage: ./dice image
################################################################################
# Pick up image name from first parameter
image="$1"
echo DEBUG: Processing image $image...
# Apply median filter to remove noisy black dots around image and then get the
# dimensions of the "trim box" - note we don't use the (degraded) median-filtered image in
# later steps.
trimbox=$(convert "$image" -median 9x9 -fuzz 50% -format %# info:)
echo DEBUG: trimbox $trimbox
# Now trim original unfiltered image into stage1-$$.png (for debug)
convert "$1" -crop $trimbox +repage stage1-$$.png
echo DEBUG: Trimmed outer: stage1-$$.png
# Now trim column headings
convert stage1-$$.png -crop 2000x2590+120+190 +repage stage2-$$.png
echo DEBUG: Trimmed inner: stage2-$$.png
# Now slice into 10x15 rectangles
echo DEBUG: Slicing and dicing
convert stage2-$$.png -crop 10x15# +repage rectangles-%03d.png
# Now trim the edges off the rectangles and resize all to a constant size
for f in rectangles*png; do
echo DEBUG: Trimming and resizing $f
trimbox=$(convert "$f" -median 9x9 -shave 15x15 -bordercolor black -border 15 -threshold 50% -floodfill +0+0 white -fuzz 50% -format %# info:)
echo DEBUG: Cell trimbox $trimbox
convert "$f" -crop $trimbox +repage -resize 32x32! "$f"
done
Here are the resulting cells - i.e. 150 separate image files. I have put a red border around the individual cells/files so you can see their extent:
Original Answer
I would do that with ImageMagick which is free and installed on most Linux distros and is available for OSX and Windows too. There are Perl, PHP, Java, node, .NET, Ruby, C/C++ bindings too if you prefer those languages. Here I am using the command line in Terminal.
First job is to get rid of noise and trim the outer edges:
convert scan.jpg -median 3x3 -fuzz 50% -trim +repage trimmed1.png
Now, trim again to get rid of outer frame and column titles across the top:
convert trimmed1.png -crop 2000x2590+120+190 +repage trimmed2.png
Now divide into 10 cells by 15 cells and save as rectangles-nnn.png
convert trimmed2.png -crop 10x15# rectangles-%03d.png
Check what we got - yes, 150 images:
ls -l rect*
rectangles-000.png rectangles-022.png rectangles-044.png rectangles-066.png rectangles-088.png rectangles-110.png rectangles-132.png
rectangles-001.png rectangles-023.png rectangles-045.png rectangles-067.png rectangles-089.png rectangles-111.png rectangles-133.png
rectangles-002.png rectangles-024.png rectangles-046.png rectangles-068.png rectangles-090.png rectangles-112.png rectangles-134.png
rectangles-003.png rectangles-025.png rectangles-047.png rectangles-069.png rectangles-091.png rectangles-113.png rectangles-135.png
rectangles-004.png rectangles-026.png rectangles-048.png rectangles-070.png rectangles-092.png rectangles-114.png rectangles-136.png
rectangles-005.png rectangles-027.png rectangles-049.png rectangles-071.png rectangles-093.png rectangles-115.png rectangles-137.png
rectangles-006.png rectangles-028.png rectangles-050.png rectangles-072.png rectangles-094.png rectangles-116.png rectangles-138.png
rectangles-007.png rectangles-029.png rectangles-051.png rectangles-073.png rectangles-095.png rectangles-117.png rectangles-139.png
rectangles-008.png rectangles-030.png rectangles-052.png rectangles-074.png rectangles-096.png rectangles-118.png rectangles-140.png
rectangles-009.png rectangles-031.png rectangles-053.png rectangles-075.png rectangles-097.png rectangles-119.png rectangles-141.png
rectangles-010.png rectangles-032.png rectangles-054.png rectangles-076.png rectangles-098.png rectangles-120.png rectangles-142.png
rectangles-011.png rectangles-033.png rectangles-055.png rectangles-077.png rectangles-099.png rectangles-121.png rectangles-143.png
rectangles-012.png rectangles-034.png rectangles-056.png rectangles-078.png rectangles-100.png rectangles-122.png rectangles-144.png
rectangles-013.png rectangles-035.png rectangles-057.png rectangles-079.png rectangles-101.png rectangles-123.png rectangles-145.png
rectangles-014.png rectangles-036.png rectangles-058.png rectangles-080.png rectangles-102.png rectangles-124.png rectangles-146.png
rectangles-015.png rectangles-037.png rectangles-059.png rectangles-081.png rectangles-103.png rectangles-125.png rectangles-147.png
rectangles-016.png rectangles-038.png rectangles-060.png rectangles-082.png rectangles-104.png rectangles-126.png rectangles-148.png
rectangles-017.png rectangles-039.png rectangles-061.png rectangles-083.png rectangles-105.png rectangles-127.png rectangles-149.png
rectangles-018.png rectangles-040.png rectangles-062.png rectangles-084.png rectangles-106.png rectangles-128.png
rectangles-019.png rectangles-041.png rectangles-063.png rectangles-085.png rectangles-107.png rectangles-129.png
rectangles-020.png rectangles-042.png rectangles-064.png rectangles-086.png rectangles-108.png rectangles-130.png
rectangles-021.png rectangles-043.png rectangles-065.png rectangles-087.png rectangles-109.png rectangles-131.png
Look at first couple:
You can do those 3 steps in 1 like this:
convert scan.jpg -median 3x3 -fuzz 50% -trim +repage \
-crop 2000x2590+120+190 +repage \
-crop 10x15# rectangles-%03d.png
You may want to shave a few pixels off each side of each image and resize to 32x32 with something like (untested):
mogrify -shave 3x3 -resize 32x32! rectangles*png