I need create 50% RGB Gray canvas from existing image to my task.
And using this command to do this:
magick.exe 00_B.tif -fill fractal -opaque fractal 000.png
or
magick.exe 00_B.tif -alpha Opaque +level-colors "rgb(50%,50%,50%)" 000.tif
Original image is 16bit RGB
But Imagemagick always save png or tif or jpg as Grayscale image.
When i define non Gray color
magick.exe 00_B.tif -fill fractal -opaque Sienna 000.tif
ImageMagick save RGB image with Sienna color on it.
What i missed and how should i create 50% Grayscale image?
I plan to use it with -write MPR:GrayLayer in final command so not actual write as a RGB file is needed.
In ImageMagick, you can create a 50% Gray image and save as RGB as follows:
For TIF output:
convert 00_B.tif -fill "gray(50%)" -colorize 100 -type truecolor result.tif
For PNG output:
convert 00_B.tif -fill "gray(50%)" -colorize 100 PNG24:result.png
Alternately:
convert 00_B.tif -evaluate set 50% -type truecolor result.tif
convert 00_B.tif -evaluate set 50% PNG24:result.png
Related
I'm trying to cut out a shape from an image based on a mask I have. I tried a number of ways but I'm really struggling to get the result I need.
I'm using ImageMagick 7.1.0-51 Q16-HDRI on Windows.
The "base" image:
https://imgur.com/a/j1kioWu
The mask i'm using:
https://imgur.com/a/OcArICa
Expected result(photoshoped):
https://imgur.com/a/GjRoxyS
Edit: Reuploaded direct on imgur to maintain transparent background
In Imagemagick, you want to invert (negate) the polarity of black and white, then do a -compose difference -composite, then invert again.
Hair:
Face:
magick hair.png face.png -alpha off -colorspace gray -negate -compose difference -composite -negate result.png
Result:
If you want pure white in the face area, threshold the two images after the conversion to grayscale
magick hair.png face.png -alpha off -colorspace gray -auto-threshold otsu -negate -compose difference -composite -negate result2.png
Result 2:
ADDITION
If your input images have transparent backgrounds, then you have to extract the alpha channels, combine them to do the difference and then put that alpha channel back on the input.
Unix Syntax:
magick hair.webp \
\( +clone face_mask.webp -alpha extract -compose difference -composite \) \
-alpha off -compose copy_opacity -composite result.png
For Windows,remove the \ in front of the parentheses and change the end of line \ to ^.
How can I draw a grid, 1px black borders no fill, over an image?
Each section of the grid should be 480x360px.
E.g., given this 1440x1080px solid white input:
It should have a 3x3 grid drawn onto it (because 9 480x360px rectangles fit into it) to make an output kind of like this:
That's not as accurate as I'd like the command to be (I was just drawing rectangles by eye), but I hope it illustrates what I'm after.
Here is a command that will read an input image, create a 480x360 transparent cell with a black border, create a grid of those cells the size of the input image, and composite that grid over the input...
infile="MyPic.png"
convert "$infile" -size 480x360 -set option:distort:viewport "%[w]x%[h]" \
\( xc:none -shave 1x1 -compose copy -bordercolor black -border 1x1 \) \
-virtual-pixel tile -distort SRT 0 -compose over -composite output.png
That will make the lines of the grid 2 pixels thick. If the lines must be 1 pixel thick, the same sort of thing can be done with a command like this...
convert "$infile" -size 480x360 -set option:distort:viewport "%[w]x%[h]" \
\( xc:none -chop 1x1 -background black -splice 1x1 \) \
-virtual-pixel tile -distort SRT 0 -compose over -composite \
-bordercolor black -shave 1x1 -compose copy -border 1x1 output.png
EDITED TO ADD: If the objective is to divide the grid into a particular number of cells rather than cells of specified dimensions, a command like this should work...
convert "$infile" \( +clone -channel A -evaluate set 0 +channel \
-crop 3x4# -chop 1x1 -background black -splice 1x1 \) -background none \
-flatten -shave 1x1 -bordercolor black -border 1x1 output.png
That creates a clone of the input image and makes it transparent, uses "-crop 3x4#" to crop it into a grid of 3x4 cells, puts a black border on the top and left edges of the cells, then reassembles them into a grid by flattening them onto the input image. It finishes by adding a border to the right and bottom edges while preserving the input image's original dimensions.
Obviously using this method the cells may not all have the exact same dimensions if the the input image can't be divided evenly by the number of cells.
EDITED AGAIN: If you don't actually need the grid to be an overlay, you can directly crop the image into tiles, put black lines around the tiles, and reassemble them to create the required output image. That can be done with a simple command like this to make 480x360 sized cells...
convert "$infile" -background black -bordercolor black \
-crop 480x360 -chop 1x1 -splice 1x1 -flatten -shave 1x1 -border 1x1 output.png
Or it can be done with "-crop 3x3#" like this to make a grid of 3 rows and 3 columns letting ImageMagick calculate the sizes as nearly as possible...
convert "$infile" -background black -bordercolor black \
-crop 3x3# -chop 1x1 -splice 1x1 -flatten -shave 1x1 -border 1x1 output.png
Again, if the image size isn't evenly divisible by the number of cells, there will be one pixel difference in the sizes of some of the cells.
I had a little attempt at this and got kind of stymied at every turn. Here is the best I got so far.
convert xc:white[1440x1080\!] -colorspace gray -fx "(i==0||i==479||i==959||i==1439||j==0||j==359||j==719||j==1079)?0:1" grid.png
So, for practical use, you would take your snow scene and clone it. Then go to greyscale (to reduce the processing time by a factor of 3) and set all the lines black and the other pixels white. Then overlay onto the snow scene choosing the darkest pixel at each location:
convert scene.jpg \( +clone -colorspace gray \
-fx "(i==0||i==479||i==959||i==1439||j==0||j==359||j==719||j==1079)?0:1" \) -compose darken -composite result.png
If you wanted it marginally smarter and adaptive to different sized images, you could calculate the third-points as a function of image size:
magick scene.jpg \( +clone -colorspace gray \
-fx "(i==0||i==int(w/3)||i==2*int(w/3)||i==w-1||j==0||j==int(h/3)||j==2*int(h/3)||j==h-1)?0:1" \) \
-compose darken -composite result.png
The best I came up with so far:
convert blank.png -fill black -draw 'line 480,0 480,1080 line 960,0 960,1080 line 0,360 1440,360 line 0,720 1440,720' level1.png
But this is all manual.
Is there a way to automate this?
Here's another variant that is fast and easy to understand - not 100% identical to your requirements but maybe good enough.
Create a starter box with a black border, duplicate twice and append across the page, duplicate twice and append down the page, make minor correction to size:
convert xc:red[478x358\!] -bordercolor black -border 1 \
-duplicate 2,0 +smush -1 \
-duplicate 2,0 -smush -1 -transparent red -scale 1440x1080\! result.png
Or you could make your initial box, duplicate it 8 times and let montage lay the resulting 9 boxes out:
convert xc:red[478x358\!] -bordercolor black -border 1 \
-transparent red -duplicate 8,0 miff:- | montage -background none -geometry +0+0 miff:- result.png
People, I am using imagemagick to crop a circle out of an image. But I am getting nothing when I run this command :
convert input.jpg +clone -threshold -1 -negate -fill white -draw "circle 539,539 539,0" -alpha off -compose copy_opacity -composite output_circ.jpg
I am getting an output like this:
Please let me know if I am missing something.
Fundamentally, you are only missing one aspect - JPEG files cannot store transparency, so you need to use a PNG or GIF, for example.
convert input.jpg -alpha on \( +clone -threshold -1 -negate -fill white -draw "circle 539,539 539,0" \) -compose copy_opacity -composite output_circ.png
How I can remove background color from image using GraphicsMagick? I need to delete rgb(255,255,255) and rgb(254,254,254) colors from image and replace them to transparency.
Thank you.
you should tinker with fuzz -parameter to match #fefefe
gm convert in.png -fuzz 3% -transparent "#ffffff" out.png
Should comment but cannot.
gm convert -geometry 50x50! -background white -extent 0x0 +matte in.png out.jpg or
gm convert -background color -extent 0x0 +matte src.png dst.png
I want to use Imagemagick to add a transparent gradient from the left and right to be composed with an image.
I can generate the image with:
convert -size 100x100 gradient: -function Polynomial -4,4,0 -distort SRT 90 gradient.png
And it looks like:
I can also compose that image on top of the image I want with:
composite original.jpg -compose Multiply gradient.png final_image.jpg
All of this works fine. My question is, how do I change the color of that gradient?
Thanks!
Simply add comma-separated colors after gradient: option:
convert -size 100x100 gradient:white,blue -function Polynomial -4,4,0 -distort SRT 90 gradient.png
Note, that -function converts channels too, so colors in gradient wont be original.
Found a way around this by doing
convert input.jpg -alpha set -virtual-pixel transparent -background red -channel A -blur 0x34 -level 75%,100% +channel -flatten final.jpg
which works in my case, giving me: