I want make 2 different colors on the output image when using Imagemagick. I have an original image with "Hello World" in it. And a modified image with "Hello Warcraft" in the same area. The default compare command will give me a image and mark all the differences with red.
Now I want to use 2 different colors like "orld" marked as red, and "arcraft" marked as another color, maybe blue. Is ImageMagick able to do this?
If not, how to use ImageMagick to transfer a specified color to another one?
Below are the sample.
Image A
Image B
Then I use the compare like: compare imageA.png imageB.png imageC.png
then the Image C will be:
Image C
But now I just know there are some differences between Image A and Image B. so I want to make some color-code on the Image C, it could be like below Image D:
Image D
from this I can know which parts are the same, and Green means what the difference on Image A and Red means what's the difference on Image B.
You can do this in ImageMagick 6 (Unix Syntax).
ImageA:
ImageB:
convert img1.png img2b.png \
-define compose:args="0,1,-1,0.5" \
-compose mathematics -composite -auto-level \
\( xc:red xc:blue +append \) -clut diff.png
This is a biased difference. Anything above 0.5 or mid gray (in normalized values) will be one color corresponding to one image and anything below 0.5 will be the other color corresponding to the other image.
See clut and compose mathematics
For ImageMagick 7, change convert to magick.
ADDITION:
Given your new input images. Here is how to do that:
imageA:
imageB:
convert imageA.png imageB.png -write mpr:img +delete -fill white -colorize 80% \
\( mpr:img -compose minus -composite -threshold 0 -background red -alpha shape \) \
\( mpr:img +swap -compose minus -composite -threshold 0 -background blue -alpha shape \) \
-background none -compose over -flatten result.png
Sorry, I used blue in stead of green. But you can change that if you want.
I have two images:
a.jpg
b.jpg
Both images are square (100x100 pixel). I want to cut a circle with a radius of 50 from image a.jpg and paste it in the middle of image b.jpg. I want to save the result in c.jpg.
How can I do this with Linux command line tools? I need to do it within a shell script.
Many different techniques can be used. ImageMagick has FX language that can perform complex calculations.
convert a.jpg b.jpg -fx 'Wi=w/2; Hi=h/2; hypot(Wi-i, Hi-j) < 50 ? u : v' c.jpg
For example...
convert -size 100x100 PLASMA: a.jpg
convert -size 100x100 GRADIENT:LIME-ORANGE b.jpg
convert a.jpg b.jpg -fx 'hypot(50-i, 50-j) < 50 ? u : v' c.jpg
Update with another technique.
A faster approach can be leveraging image mask(s) of the shape you wish to crop, and compose/composite it between both images. It'll require a format that supports alpha channels, but only for the initial work. For example...
Create a circle mask, and copy values to alpha channel.
convert -size 100x100 xc:White -fill Black \
-draw 'circle 50 50 50 5' -alpha Copy mask.png
convert \( a.png mask.png -alpha Set -compose Dst_Out -composite \) \
b.png -compose Dst_Atop -composite c.png
Eric's approach is much more succinct, and probably preferable, but here is another way anyway. I am being very environmentally aware and recycling ;-) his start images:
magick b.jpg \( a.jpg \( +clone -threshold 101% -fill white -draw "circle 49,49, 49,99" \) -channel-fx '| gray=>alpha' \) -flatten result.png
That says... "Load b.jpg as the background. Load a.jpg and then create a transparency mask by cloning the entire a.jpg setting it black and drawing a white circle in it and pushing it into the alpha channel. Then flatten that over the top of b.jpg".
The result is the same as Eric's.
I have 2 images of the same size, called image1.png and image2.png. In ImageMagick, is there any way to merge the two images by taking the odd lines from image1.png and merge with the even line from image2.png ?
Sure, make alternate rows transparent:
# Make red test image
convert -size 300x200 xc:red red.png
# Make blue test image
convert -size 300x200 xc:blue blue.png
# Merge with alternate lines made transparent
convert red.png \( blue.png -alpha on -channel A -fx 'j%2' \) -composite result.png
Or, an alternative way of thinking about it is to load both images and then choose pixels from either the first (u) or the second (v) depending on the row:
convert red.png blue.png -fx 'j%2 ? u : v' result.png
On Windows, these two come out as:
REM Do Windows style commands
convert red.png ^( blue.png -alpha on -channel A -fx "j%2" ^) -composite result.png
and
REM Windows style
convert red.png blue.png -fx "j%2 ? u:v" result.png
I want to loop through a folder of images and output to console how many pixels are #333212, how many are #332211 etc. Is this possible in PHP? I found a package that manipulates images but not one that can detect colors of each pixel. Does such a tool or function exist in the PHP library?
EDIT: Doesn't have to be in PHP, the less packages I have to install the better.
You can do this quite easily with ImageMagick, like this. Say we want to count the red pixels...
# First create a little test strip with black, white, red, green and blue parts
convert -size 50x50 xc:black xc:white xc:red xc:lime xc:blue +append out.png
Now convert anything non-red to black so that only red pixels remain
convert out.png -fill black +opaque red n.png
Now count the red pixels by cloning the resulting picture and making the clone fully black (by setting everything to zero), and running a comparison to count how many pixels are not black
convert n.png \
\( +clone -evaluate set 0 \) \
-metric AE -compare \
-format "%[distortion]" info:
2500
And 2500 looks like 50px by 50px to me :-)
Note
The AE is the Absolute Error, i.e. a simple count of the number of differing pixels. The -format "%[distortion]" info: part causes ImageMagick to output the count (%distortion) as a number (info:) rather than as an image.
Obviously, you replace red with "#333212" for your problem.
You can also do all that in one visit, like this:
convert input.png \
-fill black +opaque red \
\( +clone -evaluate set 0 \) \
-metric AE -compare \
-format "%[distortion]" info:
I have this bash script, feeding drawing information into ImageMagick, which starts like this:
#!/bin/bash
convert -size 2200x2200 xc:white \
-fill '#FFFEFF' -draw 'point 1112,1111' \
-fill '#FFFEFE' -draw 'point 1112,1112' \
-fill '#FFFEFE' -draw 'point 1111,1112' \
-fill '#FFFEFE' -draw 'point 1110,1112' \
-fill '#FFFEFE' -draw 'point 1110,1111' \
******ON & ON 4.2 MILLION LINES MORE*******
spectrumspiral.png;
My problem is I keep getting warnings about argument list too long, terminal says 'Killed', warning about 'fork: cannot allocate memory etc.
I've tried adjusting ulimit -s to a much higher value to no avail. Really want to make this image. Any idea how I can feed the terminal chunks of this script at a time? Or something to that end.
I've heard xargs can be used for things like this, but I haven't been able to find a specific implementation that fits the nature of this problem.
If you create an image with 4 pixels in it (1 red, 1 white, 1 blue and 1 black), you can tell ImageMagick to output the resulting image as text file as follows:
convert -size 1x1 xc:red xc:white xc:blue xc:black +append -depth 8 -colorspace RGB image.txt
# ImageMagick pixel enumeration: 4,1,255,rgb
0,0: (255,0,0) #FF0000 rgb(255,0,0)
1,0: (255,255,255) #FFFFFF rgb(255,255,255)
2,0: (0,0,255) #0000FF rgb(0,0,255)
3,0: (0,0,0) #000000 rgb(0,0,0)
By the same token, if you feed that text file into ImageMagick, it can recreate the image:
cat image.txt | convert txt:- output.img
So, all we need to do is convert your -fill commands into a text file of the format that ImageMagick likes. So we can do this to yourFile
sed -E 's/.*(#[0-9A-F]+).* ([0-9]+)\,([0-9]+).*/\2,\3:\1/g' yourFile
and we will get something like this:
0,0:#3C4AD8
0,1:#269531
0,2:#CF2C7C
...
...
which we can then pipe into awk to rearrange how ImageMagick likes it:
awk -F: '
BEGIN{print "# ImageMagick pixel enumeration: 2200,2200,255,rgb"}
{
coords=$1;colour=$2
rh="0x" substr(colour,2,2);
gh="0x" substr(colour,4,2);
bh="0x" substr(colour,6,2);
r=strtonum(rh);
g=strtonum(gh);
b=strtonum(bh);
printf "%s: (%d,%d,%d) %s\n",coords,r,g,b,colour;
}'
So, if we put all that together, the following script should be able to create your beloved image into the file spectrumspiral.png:
#!/bin/bash
sed -E 's/.*(#[0-9A-F]+).* ([0-9]+)\,([0-9]+).*/\2,\3:\1/g' yourFile | awk -F: '
BEGIN{print "# ImageMagick pixel enumeration: 2200,2200,255,rgb"}
{
coords=$1;colour=$2
rh="0x" substr(colour,2,2);
gh="0x" substr(colour,4,2);
bh="0x" substr(colour,6,2);
r=strtonum(rh);
g=strtonum(gh);
b=strtonum(bh);
printf "%s: (%d,%d,%d) %s\n",coords,r,g,b,colour;
}' | convert txt:- spectrumspiral.png
Try using the shell's here-document
#!/bin/bash
convert - <<EOS spectrumspiral.png
-size 2200x2200 xc:white
-fill '#FFFEFF' -draw point '1112,1111'
-fill '#FFFEFE' -draw 'point 1112,1112'
-fill '#FFFEFE' -draw 'point 1111,1112'
-fill '#FFFEFE' -draw 'point 1110,1112'
-fill '#FFFEFE' -draw 'point 1110,1111'
# ******ON & ON 4.2 MILLION LINES MORE*****
EOS
My system doesn't have convert so I can test that this works.
Most linux programs (including convert) can accept input from StdIn, which in the cmd-line above is represented by the - char. The - tells the command to expect input, not from file, but as if it was being typed at the keyboard, ie StdIn. The <<EOS .... EOS is the here-doc, and it represents bash 'typing' in all of that text into the commands stdIn input.
You may or may not need all of the quoting, if you already have there, I don't think it will hurt. If this doesn't work as is, use a small sample file of input (like above) and test various scenarios until it creates a file for you.
IHTH