Torben at 20:27, 30 October 2024

2024-10-30T20:27:57Z

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[[Category:Coding]][[Category:Software]]
ImageMagick / Image Magick

Increase gamma for all jpgs in ths folder
mogrify -gamma 1.45 $(find -name \*.jpg)

Join images on top of each other
composite -gravity SouthEast -geometry +20+20 hinzu.jpg quelle.jpg ergebnis.jpg
Options:
-gravity [NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast]
-geometry [width]x[height][+/-xoffset][+/-yoffset]

Join images besides each other, aligned in a row
convert a.png b.png +append joined.png

===Convert===
convert creates a new image while mogrify replaces the original
convert -size 120x120 cockatoo.jpg -resize 120x120 +profile "*" thumbnail.jpg
* '-size 120x120' gives a hint to the JPEG decoder that the image is going to be
downscaled to 120x120, allowing it to run faster by avoiding returning
full-resolution images to ImageMagick for the subsequent resizing operation.
* '-resize 120x120' specifies the desired dimensions of the output image.
It will be scaled so its largest dimension is 120 pixels.
* '+profile "*"' removes any ICM, EXIF, IPTC, or other profiles that might
be present in the input and aren't needed in the thumbnail.

To convert a directory full of JPEG images to thumbnails, use:
mogrify -size 120x120 -resize 120x120 *.jpg +profile "*"
123x456
123x
123x456! exact this values
123x456> only if greater

add a textbox under the image
convert xc:white -resize 1xHEIGHT! BLANK
convert -append INFILE BLANK TMPFILE
convert TMPFILE -gravity "South" -family FAMILY -pointsize FONTSIZE -draw "text 0,3 'This text is added to the picture'" OUTFILE

transparent color on existing file
mogrify -transparent white <FILE.png>

make a negative:
mogrify -negate <FILE.png>

Rotate and mirror images

* -flip = waagerecht
* -flop = senkrecht
* -transpose = diagonal (linksoben-rechtsunten)
* -transverse = diagonal (rechtsoben-linksunten)

Trim
mogrify -trim
mogrify -trim +repage QD-vs-NC.png
convert $old -trim +repage -colorspace Gray -type GrayScale $new

PDF -> jpg
convert -density 150 a.pdf a-%d.jpg
convert a.pdf -colorspace Gray -type GrayScale a-%d.jpg

JPEG Compression
convert -quality 85 a.png a.jpg

===Draw===
convert FILE -draw "rectangle 0,0 100,100" OUTFILE

convert FILE -gravity "Center" -family FAMILY -pointsize FONTSIZE -draw "text 0,3 'This text is added to the picture'" OUTFILE
FAMILY: times,arial,serif,courier,...

# perl function to paint a black frame around an image
sub draw_frame {
my $file = shift;
my $width = shift;
my $height= shift;
my $thickness = shift;

$_ = "convert $file ".
"-draw \"rectangle 0,0 ".($width-1).", ".($thickness-1)."\" ".
"-draw \"rectangle 0,0 ".($thickness-1)." ,".($height-1)."\" ".
"-draw \"rectangle ".($width-1).",0 ".($width-$thickness).",".($height-1)."\" ".
"-draw \"rectangle 0,$height $width,".($height-$thickness)."\" ". $file;
system($_);
}

ImageMagick - Revision history

Torben at 20:27, 30 October 2024