I'm using convert utility from ImageMagick to convert raw image bytes to usable image format such as PNG. My raw files are generated by code, so there is no any headers, just pure pixels.
In order to convert my image I'm using command:
$ convert -depth 1 -size 576x391 -identify gray:image.raw image.png
gray:image.raw=>image.raw GRAY 576x391 576x391+0+0 1-bit Gray 28152B 0.010u 0:00.009
The width is fixed and pretty known for me. However I have to evaluate the height of the image from the file size each time which is annoying.
Without height specified or if wrong height is specified the utility compains:
$ convert -depth 1 -size 576 -identify gray:image.raw image.png
convert-im6.q16: must specify image size `image.raw' # error/gray.c/ReadGRAYImage/143.
convert-im6.q16: no images defined `image.png' # error/convert.c/ConvertImageCommand/3258.
$ convert -depth 1 -size 576x390 -identify gray:iphone.raw iphone.png
convert-im6.q16: unexpected end-of-file `image.raw': No such file or directory # error/gray.c/ReadGRAYImage/237.
convert-im6.q16: no images defined `image.png' # error/convert.c/ConvertImageCommand/3258.
So I wonder is there a way to automatically detect the image height based on the file/blob size?
A couple of ideas...
You may not be aware of the NetPBM format, but it is very simple and you may be able to change your software that creates the raw images so that it directly generates PBM format images which are readable and useable by OpenCV, Photoshop, GIMP, feh, eog and ImageMagick of course. It would not require any libraries or extra dependencies in your software, all you need to do is put a textual PBM header on the front, so your file looks like this:
P4
576 391
... YOUR EXISTING BINARY DATA ...
Do not forget to put newlines (i.e. linefeed character) after P4 and after 391.
You can try it for yourself and add a header onto one of your files like this and then view it with GIMP or other tool:
printf "P4\n576 391\n" > image.pbm
cat image.raw >> image.pbm
If you prefer a one-liner, just use a bash command grouping like this - which is equivalent to the 2 lines above:
{ printf "P4\n576 391\n"; cat image.raw; } > image.pbm
Be careful to have all the spaces and semi-colons exactly as I have them!
Another idea, just putting some meat on Fred's answer, might be the following one-liner which uses a bash arithmetic context and a bash command substitution, you can do this:
convert -depth 1 -size "576x$(($(stat -c "%s" image.raw)*8/576))" gray:image.raw image.png
Note that if you are on macOS, stat is a little different, so you may prefer the slightly less efficient, but more portable:
convert -depth 1 -size "576x$(($(wc -c < image.raw)*8/576))" gray:image.raw image.png
You have to know the -depth and width to compute the height for ImageMagick raw format. If depth is 1, then your image is binary (b/w). So height = 8 * file size (in B)/(width). 28152*8/391 = 576
Related
I have a challenge in converting a batch of ENVI binary files(BSQ) temperature data(gotten from SAFARI 2000 AVHRR-Derived LST) to geotiff files. How can i read them and convert it to geotiff?
An example of one such file is 'afn_011-011_96.n14-LST_UL'
You would need to provide a proper sample dataset and the corresponding meta-data that tells you the image dimensions in pixels, the data type and so on, but in principle you can do it with ImageMagick which is included in most Linux distros and is available for macOS and Windows.
So, using the dataset here sample dataset and knowing the data is unsigned 8 bit and 360x180 pixels, you would run this command in Terminal (or Command Prompt if on Windows):
convert -size 360x180 -depth 8 gray:gl-latlong-1deg-landcover.bsq -auto-level result.tif
If your data is multi-band band-sequential, you may have to use:
convert -size 360x180 -depth 8 -interlace plane rgb:gl-latlong-1deg-landcover.bsq -auto-level result.tif
Or, if you cannot get that to work, you may need to extract each band separately using a byte offset and then combine them afterwards, something like:
convert -size 360x180 -depth 8 gray:image.bsq -auto-level red.tif
convert -size 360x180+64800 -depth 8 gray:image.bsq -auto-level green.tif
convert -size 360x180+129600 -depth 8 gray:image.bsq -auto-level blue.tif
convert red.tif green.tif blue.tif -combine RGB.tif
Note that if you install ImageMagick v7 or newer, the above commands change to:
magick -size ...
rather than:
convert -size ...
Keywords: ImageMagick, command-line, command line, image, image processing, satellite, ENVI, band-sequential, planar, imagery, AVHRR, convert
I know that image resizing on the command line is something ImageMagick and similar could do unfortunately I do only have very basic bash scripting abilities so I wonder if this is even possible:
check all directories and subdirectories for all files that are an image
check width and height of the image
if any of both exceeds X amount of pixels resize it to X while keeping aspect ratio.
replace old file with new file (old file shall be removed/deleted)
Thank you for any input.
Implementation might be not so trivial even for advanced users. As a one-liner:
find \ # 1
~/Downloads \ # 2
-type f \ # 3
-exec file \{\} \; \ # 4
| awk -F: '{if ($2 ~/image/) print $1}' \ # 5
| while IFS= read -r file_path; do \ # 6
mogrify -resize 1024x1024\> "$file_path"; \ # 7
done # 8
Lines 1-4 are an invocation of the find command:
Specify a directory to scan.
Specify you need files only.
Per each found item run file command. Example outputs per file:
/Downloads/391A6 625.png: PNG image data, 1024 x 810, 8-bit/color RGB, interlaced
/Downloads/STRUCTURED NODES IN UML 2.0 ACTIVITES.pdf: PDF document, version 1.4
Note how file names are delimited from their info by : and info about PNG contains image word. This also will be true for other image formats.
Use awk to filter only those files which have image word in their info. This gives us image files only. Here, -F: specifies that the delimiter is :. This gives us the variable $1 to contain the original file name and $2 for the file info. We search image word in file info and print file name if it's present.
This one is a bit tricky. Lines 6-8 read the output of awk line by line and invoke the mogrify command to resize images. Here we do not use piping and xargs, as if file paths contain spaces or other characters which must be escaped,
we will get xargs unterminated quote errors and it's a pain to handle that.
Invoke the mogrify command of ImageMagic. Unlike convert, which is also ImageMagic's command, mogrify changes files in-place without creating new ones. Here, 1024x1024\> tells to resize image to have max size of 1024x1024. The \> part tells to preserve aspect ratio, so that the final image will have the biggest side of 1024px. Other side will be smaller than that, unless the original image is square. Pay attention to the ;, as it's needed inside loops.
Note, it's safe to run mogrify several times over the same file: if a file's size already corresponds to your target dimensions, it will not be resized again. However, it will change file's modification time, though.
Additionally, you may need not only to resize images, but to compress them as well. Please, refer to my gist to see how this can be done: https://gist.github.com/oblalex/79fa3f85f05924017d25004496493adb
If your goal is just to reduce big images in size, e.g. bigger than 300K, you may:
find /path/to/dir -type f -size +300k
and as before combine it with mogrify -strip -interlace Plane -format jpg -quality 85 -define jpeg:extent=300KB "$FILE_PATH"
In such case new jpg files will be created for non-jpg originals and originals will need to be removed. Refer to the gist to see how this can be done.
You can do that with a bash unix shell script looping over your directories. You must identify all the file formats you want such as jpg and png, etc. Then for each directory, loop over each file of the given list of formats. Then use ImageMagick to resize the files.
cd
dirlist="path2/directory1 path2/directory2 ...."
for dir in $dirlist; do
cd "$dir"
imglist=`ls | grep -i ".jpg\|.png"`
for img in $imglist; do
convert $img -resize "200x200>" $img
done
done
See https://www.imagemagick.org/script/command-line-processing.php#geometry
I have a bunch of png files named as 1.png, 2.png, etc. and I want to create an animated gif image from them all. I haven't been successful in finding a solution for a terminal command that will convert these png files into a single animated gif.
Can someone post some commands that I can try? I have tried "convert" commands but my terminal always says convert is not found even though I have installed ImageMagik.
convert *.png screens.gif
This answer suggested installing convert with brew install ImageMagick.
ImageMagick's convert command works perfectly for this but you'll want to list the filenames in the correct order. Using *.png will jumble frames if the digits don't have the leading zeros because the ordering is alphabetical:
1.png 10.png 11.png 2.png 3.png ...
If you use zsh you can simply use a glob qualifier:
convert *.png(n) out.gif
Otherwise you can sort the ls output
convert $(ls *.png | sort -V) out.gif
If your filenames have leading zeros go ahead and use *.png. Note that the default delay between frames is small, so depending on your use case the frame rate might be too quick. To change that use the -delay option, for example:
convert -delay 50 *.png out.gif
This will set FPS to 100/50 = 2 frames per second.
I need to get a specific crop of an image and put it over another image at a certain position and resized.
I can crop the first image and save it to a file in one command and then I can composite the 2 images in another command.
However, I would like to do it in a single command - is this possible with graphicsmagick and how?
Here are the 2 commands I am using atm:
gm convert -crop 1457x973+254+413 amber.jpg tmp.jpg
gm composite -geometry 6000x4000+600+600 tmp.jpg lux_bg.png out.jpg
The reason for wanting this is to avoid writing to disk then reading again when all this could be done in memory.
With ImageMagick, for example, the same 2 commands would be written in a single command like this:
convert lux_bg.png \( amber.jpg -crop 1457x973+254+413 \) -geometry 6000x4000+600+600 -composite out.jpg
I am doing this with ImageMagick for now but would love to do it with GraphicsMagick.
If your reason is simply to avoid creating a temporary file, you can still do it with two commands by constructing 'pipelines' (a great concept invented by, afaik, Douglas McIlroy around 1964):
gm convert -crop 1457x973+254+413 amber.jpg - | gm composite -geometry 6000x4000+600+600 - lux_bg.png out.jpg
hint: note the two - dashes in the two commands, and the | pipe
since the - can be used to mean the standard output and input in the two commands respectively.
This means that no file is created, all should happen in the memory.
You can find this in the help (gm -help convert | grep -i -e out -B 1):
Specify 'file' as '-' for standard input or output.
The use of - is common in unix-likes and must have been inspired by, or by something related to, the POSIX standard's Utility Syntax Guidelines.
Have you tried && operator? Your command should become:
gm convert -crop 1457x973+254+413 amber.jpg tmp.jpg && gm composite -geometry 6000x4000+600+600 tmp.jpg lux_bg.png out.jpg
I'm working on a shell script to convert MPO stereographic 3D images into standard JPEG images. A MPO file is just two JPEG images, concatenated together.
As such, you can split out the JPEG files by finding the byte offset of the second JPEG's magic number header (0xFFD8FFE1). I've done this manually using hexdump/xxd, grep, head, and tail.
The problem here is grep: what can I use to search a binary directly for a specific magic number, and get back a byte offset? Or should I not use a shell script for this at all? Thanks.
You can do this using bbe (http://bbe-.sourceforge.net/) which is a sed like program for binary files:
In order to extract the first JPEG use:
bbe -b '/\xFF\xD8\xFF\xE1/:' -e 'D 2' -o first_jpeg mpo_file
And for the second one:
bbe -b '/\xFF\xD8\xFF\xE1/:' -e 'D 1' -o second_jpeg mpo_file
Note that this will not work if the JPEG's magic number occurs somewhere else in the MPO file.
I think that Bart is on to your biggest problem.. If that binary sequence repeats during the process, you will get partial JPEGs.
I did a quick test by concatenating some JPEGs and then extracting them with awk (please note that the magic number in my files ended in 0xE0 and not 0xE1):
# for i in *.jpg ; do cat $i ; done > test.mpo
# awk 'BEGIN {RS="\xFF\xD8\xFF\xE0"; FILENUM=-1} {FILENUM++; if (FILENUM == 0) {next}; FILENAME="image0"FILENUM".jpg"; printf "%s",RS$0 > FILENAME;}' test.mpo
# file image0*.jpg
image01.jpg: JPEG image data, JFIF standard 1.01
image010.jpg: JPEG image data, JFIF standard 1.01
image011.jpg: JPEG image data, JFIF standard 1.01
This seemed to work ok for me, but the above mentioned issues are still unhandled and very real.
I've found a much better explanation of MPO file structure (and how to process it correctly) at http://www.davidglover.org/2010/09/using-the-fuji-finepix-real-3d-w3-camera-on-a-mac-or-linuxunix.html
Edit, October 2019:
Since the blog entry now 404s, here is the script that I wrote based on it. I haven't used it in many years.
#!/usr/bin/env bash
# Script to convert 3D MPO files, as used in the Fuji FinePix series of 3D cameras, into standard JPEG files.
# Based on work by David Glover, posted at http://www.davidglover.org/2010/09/using-the-fuji-finepix-real-3d-w3-camera-on-a-mac-or-linuxunix.html
# This script requires exiftool and ImageMagick.
FULLNAME="$1"
FILENAME="$(basename $FULLNAME)"
DIRNAME="$(dirname $FULLNAME)"
BASENAME="${FILENAME%.*}"
# Create output directories
mkdir -p "$DIRNAME"/stereoscopic-rl/
mkdir -p "$DIRNAME"/stereoscopic-mpo/
mkdir -p "$DIRNAME"/stereoscopic-anaglyph/
mkdir -p "$DIRNAME"/monoscopic-l/
mkdir -p "$DIRNAME"/monoscopic-r/
# Create separate left and right images
exiftool -trailer:all= "$FULLNAME" -o "$DIRNAME"/monoscopic-l/"$BASENAME"-left.jpg
exiftool "$FULLNAME" -mpimage2 -b > "$DIRNAME"/monoscopic-r/"$BASENAME"-right.jpg
# Move the MPO file to its new home
mv "$FULLNAME" "$DIRNAME"/stereoscopic-mpo/
# Determine parallax value and create cropped images for stereo generation
# 36 is only appropriate for 4:3 or 3:2 images
parallax=$(exiftool -b -Parallax "$DIRNAME"/monoscopic-r/"$BASENAME"-right.jpg)
parallax=$(echo "$parallax"*36+0.5 | bc | cut -d . -f 1)
# The above pipeline can't deal with a parallax of zero
# In theory, this fix doesn't cover values between zero and -1
# TODO improve the calculation
if [ ! $parallax ]; then
parallax=0
fi
echo $parallax
if [ $parallax -ge 0 ]; then
convert "$DIRNAME"/monoscopic-l/"$BASENAME"-left.jpg -crop +"$parallax"+0 "$DIRNAME"/monoscopic-l/"$BASENAME"-left-cropped.jpg
convert "$DIRNAME"/monoscopic-r/"$BASENAME"-right.jpg -crop -"$parallax"+0 "$DIRNAME"/monoscopic-r/"$BASENAME"-right-cropped.jpg
else
convert "$DIRNAME"/monoscopic-l/"$BASENAME"-left.jpg -crop -"$((-1*$parallax))"+0 "$DIRNAME"/monoscopic-l/"$BASENAME"-left-cropped.jpg
convert "$DIRNAME"/monoscopic-r/"$BASENAME"-right.jpg -crop +"$((-1*$parallax))"+0 "$DIRNAME"/monoscopic-r/"$BASENAME"-right-cropped.jpg
fi
# Create stereoscopic images for cross-eye (right-left) and anaglyph (red-cyan) viewing
convert "$DIRNAME"/monoscopic-r/"$BASENAME"-right-cropped.jpg "$DIRNAME"/monoscopic-l/"$BASENAME"-left-cropped.jpg +append "$DIRNAME"/stereoscopic-rl/"$BASENAME"-stereoscopic-rl.jpg
composite -stereo 0 "$DIRNAME"/monoscopic-r/"$BASENAME"-right-cropped.jpg "$DIRNAME"/monoscopic-l/"$BASENAME"-left-cropped.jpg "$DIRNAME"/stereoscopic-anaglyph/"$BASENAME"-stereoscopic-anaglyph.jpg
# Clean up separated parallax-corrected images
rm "$DIRNAME"/monoscopic-l/"$BASENAME"-left-cropped.jpg
rm "$DIRNAME"/monoscopic-r/"$BASENAME"-right-cropped.jpg
exit 0
I think a very simple home brew approach will be your best bet. The code for doing this would be very small, depending on all the special cases of your binary file format.
Use mmap to get a convenient view of your file in memory.
Start scanning, and save the byte-offset in a variable, say start.
Scan until you reach your delimiter, saving the ending offset, in say end.
Create a new file
Memory-map the new file
Copy the byte-range from start to end into the new file.
Close the new file and start scanning again.
FFE1 is not part of the some jpeg "magic number", it's the APP1 marker. And it's not guaranteed to come right after the SOI marker FFD8. Also, you should be careful that some jpeg images embed a thumbnail jpeg in an EXIF block. That will most likely also contain an APP1 marker.