This repo contains simple tools for quick and efficent making your own PDF file from images.
- Installation
- Convert images to one file format
- Rename and sort files
- Rotate images
- Cropping and aligning all images
- Search an image with the lowest resolution and width
- Weight reduction and image quality (optional)
- Verification of compliance of the order and the parties
- Convert images to a PDF
For almost every step we will need to use imagemagick and partly awk. To install it on Debian based distros use:
sudo apt-get install imagemagick awk
If you have different formats of files it's recommended to convert it for one common (ex: PNG).
mogrify -format jpg *.png
To achieve this task you can use renaming_files.sh and extending_filename.sh
First one, trim names of scanned files to one general convention. For example: Picture.png, Picture (2).png, Picture (3).png, ... , Picture (100).png you can change in one second into: 1.png, 2.png, 3.png, ... , 100.png
Bash a bit different recognise the list of elements. The order of files in bash console can be present like this: 1.jpg, 10.jpg, 100.jpg, 2.jpg, ..., 99.jpg. We will change it into: 001.jpg, 002.jpg, 010.jpg, ..., 099.jpg, 100.jpg.
Sometimes images are saved with wrong angle (90, 180 or 270 degree). To solve this unconvenient problem you can use rotate_images.sh script.
It helps to handle with massive rotating images stored in folder. Sometimes scanned images are in oposite rotations 0 and 180, or 90 and 270. This script can be easly set commands for even and odd images for easy detection.
In some cases (RGB) rotating the image increase its contrast (Like cover). To reduce this you can change task to rotate_images.sh for increase contrast for those images which have less contrast to others.
Example command:
convert "${TEMP_ARRAY[i]}.$EXT" -contrast "${TEMP_ARRAY[i]}.$EXT"
Usualy it is a manual step. Need to look through all the files and correct. Best tool for this step (and all others if you need) is just Shotwell Viewer. Yeah as simple as you see, you do not need any extra program (in fact it's usually preinstalled in most new distros).
Use Shotwell aligning feature to adjust images to proper angle (it usualy a small corrections for images).
To have best quality of PDF you need to equalize all images to the lowest.
Below script help you with finding lowers resolution from all images you have.
This script can take a while in fact that retriving data from images is slow process ;) 200 images = ~2min
identify -verbose *.png | egrep -wi --color "Image:|Resolution:|Geometry:|Filesize:|Colorspace:" > images_stats.txt
And sample output:
...
Image: 204.png
Geometry: 1763x2496+0+0
Resolution: 72x72
Colorspace: Gray
Filesize: 157KB
...
Image: 211.png
Geometry: 1789x2458+0+0
Resolution: 72x72
Colorspace: Gray
Filesize: 131KB
Image: 212.png
Geometry: 1942x2745+0+0
Resolution: 72x72
Colorspace: Gray
Filesize: 1.972MB
The Resolution and first value of Geometry parameter (the width of image). It should be the same for all images. To achieve that, we need to find the lowest value of first Geometry parameter.
Use below command to find the lowes value into previously generated images_stats.txt file:
cat images_stats.txt | grep "Geometry:" | awk -F"x" '{print $1}' | awk -F" " 'NR == 1 || $2 < min { line =$0; min =$2}; END {print line}'
The result should be like this below (keep it in mind):
Geometry: 1757
We should do the same with Resolution
cat images_stats.txt | grep "Resolution:" | awk -F"x" '{print $1}' | awk -F" " 'NR == 1 || $2 < min { line =$0; min =$2}; END {print line}'
Sample result:
Resolution: 72
This 2 factors (
ResolutionandGeometrywidth) for all files should be the same!!!
According to results, we need to run commad to equalize Geometry width for all images:
Note: Changes images done on current photographs!!! So let's make a copy to a new folder and work on it.
mogrify -geometry 1757x *.png
If images seams to be to heavy we can easly change it by running below command:
mogrify -resize 60% -quality 80% *.png
This command resize all images in current folder and reduce quality to target point. Feel free to change those numbers to suite your needs. REMEMBER TO TAKE A COPY OF ALL FILES, BECAUSE IT APPLY CHANGES ON CURRENT FILES!
Now left the final step before the conversion - verification of our files.
By verification I mean a simple check of correct numbering of subsequent pages and thus whether I made a PDF file.
Pay attention to the numbering of the pages to agree with the parties elected PDF search engine (go to page).
To convert just run below command into folder with images:
It also can take a while. It depends on computer parameters.
convert *.png book.pdf
The End :)