I want to add watermark to my_own_png.png file by using:
composite -dissolve 10% -gravity center -quality 100 watermark_350.png my_own_png.png result.png
The result.png is not what I what, I want to keep my_own_png.png's alpha.
Please help~Thank you.
There are a couple of ways of doing this...
Firstly, you could run with your current processing, which I presume you understand and are happy with, and then copy back your original image's alpha over the top of your result, like this:
# Your current processing
composite -dissolve 10% ... result.png
# Now add back the original image's alpha
convert result.png my_own_png.png -compose CopyOpacity -composite result.png
Or, you could do the whole lot in one go using convert rather than composite, and it will look something like this but it is hard to be sure without seeing what you are actually doing:
convert my_own_png.png \
\( +clone -gravity center watermark_350.png -compose dissolve -define compose:args='10' -composite \) \
+swap -compose CopyOpacity -composite result.png
That basically loads up your my_own_png.png and puts it to one side. It then copies it and does the dissolve with your watermark inside the parentheses. After the parentheses, the order of the images is swapped so that the watermarked image is first in the list and the original png is second in the list. It then copies the alpha from the original image and applies it to the watermarked image - hopefully :-)
Related
I want to generate an image out of 3 images. One of these images is the background, one the shape mask and one the color of the shape.
Here are the images:
shape.png
(transparent background, white circle in the middle and black circle inside and gray circle inside the black one)
shapecolor.png
background.png
The background.png should be the overall background. On top of that is the shape and all white parts (and also the white in the gray parts) should be in the color of shapecolor.png
I used simple mono color images to make it easier but I use some textures in reality ^^
I have no idea how to solve this problem in Imagemagick, the tool is very powerful and the documentation is not so easy to understand. Tried to solve this for 3h, but did not get the result, which should look like this:
Can anyone help please?
Here is one way to do it in Imagemagick. In the second line, extract the alpha channel from omg.png and save it in an mpr: in-memory image and then delete the clone. Then I use the mpr: image later in the last step.
convert red.png img.png \
\( +clone -alpha extract -write mpr:alpha +delete \) \
-compose multiply -composite \
green.png +swap mpr:alpha -compose over -composite \
result.png
I'm assuming ImageMagick is the best option for this, but please let me know if you have other recommendations that can be scripted.
I am trying to replace all the 32x32 tiles of an image with a single tile. This is an example for the original image:
This is the tile that I want to use to replace all tiles on the original image:
And this is what I want the output to be:
I've figured out from other posts on Stack Overflow that I can use ImageMagick's composite option to overlay the tile onto the original image:
$ convert original.png tile.png -composite overlay.png
Resulting in the following:
And I assume by knowing the original images dimensions I can overlay the tile manually multiple times. But is there a way to automate the process. In the example pictures I have given, I need to overlay the tile 8 times on the original 64x128 image.
How can I do this with ImageMagick or another software? And if ImageMagick, would the montage or composite command be a better option?
Edit: As an additional question, would it be possible to skip tiles that are completely transparent?
Input example:
Output example:
It isn't really important to be able to do this part, but would be nice.
If the tile image fits evenly into the dimensions of the original, a command like this should do most of what you want...
convert original.png tile.png -background none -virtual-pixel tile \
-set option:distort:viewport %[fx:u.w]x%[fx:u.h] -distort SRT 0 +swap \
-compose copyopacity -composite overlay.png
That reads in both images. Then it creates another canvas the size of the original and filled with multiple copies of the tile image. Then it uses the original as a transparency mask to create a copy of the new tiled image with the same transparent cells as the original.
I don't know why you would need to overlay the 8 tiles on the original. Just create it from scratch and name the output the same as your original
You could use Imagemagick montage to do that (unix syntax):
nx=`convert original.png -format "%[fx:w/32]" info:`
ny=`convert original.png -format "%[fx:h/32]" info:`
num=$((nx*ny-1))
montage tile.png -duplicate $num -tile ${nx}x${ny} -geometry +0+0 result.png
Here I use convert to duplicated the tile, but it uses a relatively current -duplicate feature. If you do not have a current enough version of Imagemagick, then just repeat the tile in montage as follows:
montage Ro1Lp.png Ro1Lp.png Ro1Lp.png Ro1Lp.png Ro1Lp.png Ro1Lp.png Ro1Lp.png Ro1Lp.png -tile 2x8 -geometry +0+0 result.png
As Fred (fmw42) says, "why don't you just create the whole image from scratch?".
Maybe your description isn't complete, so here are a couple more pieces that might help you work it out.
Given bluetiles.png and singlered.png:
you can position red ones as you wish like this:
convert bluetiles.png \
singlered.png -geometry +0+32 -composite \
singlered.png -geometry +32+96 -composite result.png
Given bluewithtransparent.png:
you can copy its transparency to the newly-created image like this:
convert bluetiles.png \
singlered.png -geometry +0+32 -composite \
singlered.png -geometry +32+96 -composite \
\( bluewithtransparent.png -alpha extract \) -compose copyopacity -composite result.png
I've got one background image: sky.jpg
And two transparent PNG images: gradient.png and tree.png
Now I want to draw the two images on the background with a perspective distortion, like this:
The destination coordinates of the two images are, in clockwise order (starting top left) :
gradient: 62,129 421,218 383,458 147,548
tree: 445,100 765,47 698,368 529,396
I cannot figure out how to start with one image (in this case the sky background) and then take another image and draw that with perspective distortion to specific destination coords within the background. Also doing this with more than one image at a time, within one convert command, troubles me.
For example, when I start with just one image (the gradient) and try this:
convert sky.jpg \( gradient.png -alpha set -virtual-pixel transparent \
+distort Perspective "0,0 62,129 255,0 421,218 255,255 383,458 0,255 147,548" \) \
-compose src-over -composite result.jpg
It gets correctly warped (so the coordinates are relatively correct) but it's drawn in the top left corner, not at the coordinates I specify.
Also I'm a bit unsure if my usage of -compose and -composite is correct (I took this from various IM manual examples).
One other thing that is unclear to me: in case of the 256x256 image, should I use 255,0 and 255,255 and 0,255 as the corner coordinates, or 256,0 and 256,256 and 0,256 ?
Any IM experts who can shed light on these issues?
Add a -geometry just before the -composite like this:
convert -size 800x600 xc:black \( -size 300x200 xc:red \) -geometry +90+10 -composite result.png
I have two images. One is background with no alpha. The other is a white cloud. The alpha of the cloud image is premultiplied with black. When I composite them the white cloud has black in it, so it looks grey instead of white like it should. I'm doing:
convert -gravity Center bg.tga whitecloud.tga -composite comp.tga
Is there a way to composite premultiplied images in ImageMagick, or does the image have to be non-premultiplied? Can I make a premultiplied image non-premultiplied using ImageMagick?
Update:
Ok, here are the images as TGA for download:
http://acatysmoof.com/posting/problems/imagemagick/premultiplication/bg.tga
http://acatysmoof.com/posting/problems/imagemagick/premultiplication/whitecloud.tga
http://acatysmoof.com/posting/problems/imagemagick/premultiplication/aftereffects.tga
http://acatysmoof.com/posting/problems/imagemagick/premultiplication/imagemagick.tga
and in the same order as jpgs to view in your browser:
I tried all the modes provided, but none of them create the same result as After Effects.
It would be easier if you showed your images, but try adding -compose lighten before -composite in your command, like this:
convert a.tga b.tga -compose lighten -composite out.tga
Basically that will make ImageMagick choose the lighter pixel of the two images at every point.
If that doesn't work, try other blending modes
for b in $(identify -list compose); do
convert -label "$b" bg.tga whitecloud.tga -compose $b -composite miff:-
done | montage - -tile 5x out.png
I am kind of thinking Atop, Dissolve, SrcAtop and SrcOver might be your friends but have a look full-size and see what floats your boat. That would be
convert a.tga b.tga -compose Atop -composite out.tga
Here is an Imagemagick command that does what you want:
convert -gravity Center whitecloud.tga -fx "u/max(u.a, 1/255)" bg.tga +swap -composite -fx "u*u.a" comp.tga
What's happening here?
-fx command #1: Convert whitecloud.tga from premultiplied alpha to "normal". The max() operator is a special case to avoid dividing by zero.
+swap command: Make bg.tga the first image and the revised whitecloud.tga the second.
-composite these two regular, non-premultiplied images.
-fx command #2: take the result, and return to a premultiplied alpha format.
This gives exactly the same result as After Effects.
Note that, as I wrote it, it only works for an opaque bg.tga. You'd need to do some extra work to handle a transparent background image.
If you want to duplicate the After Effects result, then I believe what you want to do in ImageMagick is the following -- composite the background image with a white image using the cloud as a mask:
convert bg.tga \( -clone 0 -fill white -colorize 100 \) whitecloud.tga -compose over -composite cloud_blue.tga
I have posted a JPG result, but my .tga result is the same.
I need to create an image to be used as a rollover background image. It's a circular pattern that is split into 8 pieces. Here's a screengrab of the main image (png with transparency):
And here's a screengrab of the mask image. It's the same size as the main image and features 'pie' pieces in order to mask all but the sector that is being hovered over.
I'm including screengrabs, as I believe the answer should be pretty simple (aren't all answers simple when you know them?!) so I'll save bandwidth, but I can upload the original files if it's helpful.
Here's the command I'm using to create the new masked image:
convert main.png \( mask.png -colorspace gray -alpha off \) \
-compose copy-opacity -composite new.png
The trouble is that the new image created has flattened the original image's alpha to a black background:
How do I get Imagemagick to preserve the original png's transparency?
You want masked composition to do this. http://imagemagick.org/Usage/compose/#mask
The technique is to compose the original image (the src) onto a fully transparent image of the same size (the dst), using a mask to limit composition area (the mask). It is a special case of the -composite operator, and involves 3 images, rather than 2 like the rest of the compose methods. You don't specify any -compose mode for this.
A quick way to get the fully transparent dst that you need for this technique is to clone the src image and zero out its alpha channel, then swap the order of src and dst so that they are in the right order for the -composite operation to follow:
convert main.png -alpha on \( +clone -channel a -fx 0 \) +swap mask.png -composite out.png
I was not satisfied with retroj's solution as it seems to ignore the grayscale of the mask.
This one worked for me:
composite -compose Dst_In \( mask.png -alpha copy \) main.png -alpha Set PNG32:result.png
or
convert -compose Dst_In \( mask.png -alpha copy \) main.png -alpha Set -composite PNG32:result.png
Dst_In method multiplies the alpha channels of two images. The trick here is to convert the grayscale mask to an alpha channel for it which is done with -alpha copy.