-duplicate
convert img*.png -duplicate 3 out.gif
makes
0 1 2 2 2 2
where 0 is img0.png, and 1 is img1.png, etc, making a GIF. But can I make below?
0 0 0 0 1 2 2 2 2
that is, append to end and start? I get I can use indexing to make
0 1 2 2 2 2 0 0 0
which is identical in a loop, but I need the 0s at start in context.
TL;DR for 0 0 0 1 2 3 ... 20 21 21 21 (any number of images) do
convert img*.png -write mpr:imgs -delete 0--1 mpr:imgs[0,0,0,1--1,-1,-1] out.gif
Using ImageMagick v6 on Windows command line, this command will let you arrange the order and number of images in any way you need.
convert img*.png -write mpr:imgs -delete 0--1 mpr:imgs[0,1,2,2,2,2,0,0,0] out.gif
That reads the 3 input images, copies them all into a memory register named "mpr:imgs", deletes the input images from the command, then reads the images from that memory register as you specify in the square brackets. The image index 0 is the first image read into the command, 1 is the second, etc.
Also, using -duplicate you can specify which image in the list you want to use according to their order in the list. This command will give the same result as the one above...
convert img*.png -duplicate 3 -duplicate 3,0 out.gif
The command reads the three images, then -duplicate 3 makes 3 more of the last image in the list, then -duplicate 3,0 makes 3 more of the first image in the list, index 0.
Another approach would be to use ( -clone ... ) inside parentheses to create the number of duplicates in the order you want.
convert img*.png ( -clone 2,2,2 -clone 0,0,0 ) out.gif
That reads the 3 input images, clones the third image 3 times, then clones the first image 3 times, giving the same result as the commands above.
These commands are in Windows syntax. For a *nix OS you'd have to escape the parentheses with backslashes "\(...\)".
Also helpful are -swap, -reverse, -insert, and -delete to manipulate the order of images in the list.
You should be able to load your first image, make any duplicates you need, then load the second and make duplicates and load the third and make any duplicates:
convert img0.png -duplicate 3 img1.png img2.png -duplicate 3 ...
will give your desired image sequence:
0 0 0 0 1 2 2 2 2
Related
I am working on a ML problem to predict house prices and Zip Code is one feature which will be useful. I am also trying to use Random Forest Regressor to predict the log of the price.
However, should I use One Hot Encoding or Label Encoder for Zip Code? Because I have about 2000 Zip Codes in my dataset and performing One Hot Encoding will expand the columns significantly.
https://datascience.stackexchange.com/questions/9443/when-to-use-one-hot-encoding-vs-labelencoder-vs-dictvectorizor
To rephrase: does it make sense to use LabelEncoder instead of One Hot Encoding on Zip Codes
Like the link says:
LabelEncoder can turn [dog,cat,dog,mouse,cat] into [1,2,1,3,2], but
then the imposed ordinality means that the average of dog and mouse is
cat. Still there are algorithms like decision trees and random forests
that can work with categorical variables just fine and LabelEncoder
can be used to store values using less disk space.
And yes, you are right, when you have 2000 categories for zip codes, one hot may blow up your feature set massively. In many cases when I had such problems, I opted for binary encoding and it worked out fine most of the times and hence is worth a shot for you perhaps.
Imagine you have 9 features, and you mark them from 1 to 9 and now binary encode them, you will get:
cat 1 - 0 0 0 1
cat 2 - 0 0 1 0
cat 3 - 0 0 1 1
cat 4 - 0 1 0 0
cat 5 - 0 1 0 1
cat 6 - 0 1 1 0
cat 7 - 0 1 1 1
cat 8 - 1 0 0 0
cat 9 - 1 0 0 1
There you go, you overcome the LabelEncoder problem, and you also get 4 feature columns instead of 8 unlike one hot encoding. This is the basic intuition behind Binary Encoder.
**PS:** Give 2 power 11 is 2048 and you have 2000 categories for zipcodes, you can reduce your feature columns to 11 instead of 1999 in the case of one hot encoding!
I'm trying to create svg-sprite using npm package svg-sprite. Eventually I get sprite, that looks like this:
// icons-test.svg
...
<svg viewBox="0 0 108 54" ...>
<svg height="54" width="54" viewBox="-2 -2 54 54" ...>
<path d="...”>
</svg>
<svg height="54" width="54" viewBox="-2 -2 54 54" ...>
<path d="...”>
</svg>
</svg>
To define size (for example width) of this svg-sprite I use command identify from util ImageMagick.
identify -format '%w' icons-test.svg
or write it to the file
echo "\$spriteWidth = $(identify -format ‘%w’ icons-test.svg)px" >> styles.styl
The problem is that in file I don't get width of full svg-sprite (108), but only width of last sub-svg image(54), that is included in common svg-sprite.
Please, tell me where is my mistake? How to make identify return correct width.
Or advice me another variants to solve the problem.
I would suspect that the nested svg tags are confusing ImageMagick's internal SVG decoder. Try converting the SVG into MVG. It should throw-out the nested SVG structure.
$ convert icons-test.svg mvg:-
Which will print the following MVG instructions.
push graphic-context
viewbox 0 0 108 54
affine 1 0 0 1 0 0
push graphic-context
viewbox 0 0 54 54
affine 1 0 0 1 2 2
push graphic-context
path ''
pop graphic-context
pop graphic-context
push graphic-context
viewbox 0 0 54 54
affine 1 0 0 1 2 2
push graphic-context
path ''
pop graphic-context
pop graphic-context
pop graphic-context
With the nested viewboxs isolated to graphic-contexts on the stack, you should be able to identify correctly.
$ convert icons-test.svg mvg:- | identify -format '%w' mvg:-
#=> 108
Is there a software/tool that can generate me a matrix of RGB values from a simple raw 8-bit RGB image?
Also, is there a software/tool that can generate an image from a given matrix of RGB values?
Thank you.
PS:
i) I am aware that this can be done using Matlab. I am looking for a tool that can do it that is not Matlab.
ii) I am aware of existing question about doing similar stuff programmatically. I need a software tool, if there is any, that can do this task.
I would suggest you use the venerable NetPBM which is available for Linux, macOS and Windows. Alternatively, you could use ImageMagick but that is much heavier weight, see later.
NetPBM Method - see Wikipedia NetPBM entry
So, let's start with a raw, 8-bit RGB file that contains a red, a green and a blue pixel:
-rw-r--r-- 1 mark staff 9 10 Oct 07:47 rgb888.bin
As you can see, it has 9 bytes. Let's look at them:
xxd -g3 rgb888.bin
00000000: ff0000 00ff00 0000ff
Now, if we want that image as a matrix of legible values:
rawtoppm -plain 3 1 rgb888.bin
Sample Output
P3
3 1
255
255 0 0 0 255 0 0 0 255
where:
-plain means to display in ASCII rather than binary
P3 tells us it is colour and ASCII
3 1 tells us its dimension are 3 pixels wide by 1 pixel high
255 essentially tells us it is 8-bit (65536 would mean 16-bit)
the last row is the pixels
Converting back to binary is a little harder, let's assume we start with a PPM file created like this:
rawtoppm -plain 3 1 rgb888.bin > image.ppm
So, we can get the binary version like this:
ppmtoppm < image.ppm | tail -c 9 > rgb888.bin
and look at it with:
xxd -g3 rgb888.bin
00000000: ff00 0000 ff00 0000 ff
ImageMagick Method
# Convert binary RGB888 to text
convert -depth 8 -size 3x1 RGB:rgb888.bin txt:
Sample Output
# ImageMagick pixel enumeration: 3,1,65535,srgb
0,0: (65535,0,0) #FF0000 red
1,0: (0,65535,0) #00FF00 lime
2,0: (0,0,65535) #0000FF blue
Or, slightly different appearance:
# Convert binary RGB888 to matrix
convert -depth 8 -size 3x1 RGB:rgb888.bin -compress none ppm:
Sample Output
P3
3 1
255
255 0 0 0 255 0 0 0 255
And now going the other way, PPM to binary
# Convert PPM image to binary
convert image.ppm rgb:image.bin
# Check how the binary looks
xxd -g 3 image.bin
00000000: ff0000 00ff00 0000ff .........
Plain dump method
Maybe you are happy with a plain dump from od:
od -An -t u1 rgb888.bin
Sample Output
255 0 0 0 255 0 0 0 255
I know that tensors have an apply method, but this only applies a function to each element. Is there an elegant way to do row-wise operations? For example, can I multiply each row by a different value?
Say
A =
1 2 3
4 5 6
7 8 9
and
B =
1
2
3
and I want to multiply each element in the ith row of A by the ith element of B to get
1 2 3
8 10 12
21 24 27
how would I do that?
See this link: Torch - Apply function over dimension
(Thanks to Alexander Lutsenko for providing it. I just moved it to the answer.)
One possibility is to expand B as follow:
1 1 1
2 2 2
3 3 3
[torch.DoubleTensor of size 3x3]
Then you can use element-wise multiplication directly:
local A = torch.Tensor{{1,2,3},{4,5,6},{7,8,9}}
local B = torch.Tensor{1,2,3}
local C = A:cmul(B:view(3,1):expand(3,3))
I am trying to import a movement curve from Maya into my XNA game, but I cannot figure out how. Basically I want to catch the curve by it's name, and look up its values at different points of time.
Are curves exported into FBX at all? And, if not, then how to catch it?
Edit: Maya can export to Maya ASCII, and I tried to parse it, but I am not sure what formula I should use to recreate the curve.
Here is a Maya ASCII segment defining a typical curve:
createNode transform -name "curve1";
createNode nurbsCurve -name "curveShape1" -parent "curve1";
setAttr -keyable off ".visibility";
setAttr ".cached" -type "nurbsCurve"
3 11 0 no 3
16 0 0 0 1 2 3 4 5 6 7 8 9 10 11 11 11
14
-4.9774564508407968 0 -6.8331005825440476
-5.5957526204336077 0 -5.5944567905896161
-6.8323449596191823 0 -3.1171692066807277
-5.6935230034445992 0 3.3047128765440847
-1.6528787527978079 0 8.8676235621397499
7.5595909161095838 0 10.325347443191644
9.2297347448508607 0 8.5586791722955731
10.0730315036276 0 0.93412333819133941
5.9770106513247976 0 3.7809964481624871
2.9006817236214149 0 -3.3327711853359037
11.373191256465434 0 -4.6672854260704906
4.5697574985247682 0 -14.178349348937205
2.4191279569332935 0 -11.415532638650156
1.3438131861375628 0 -10.034124283506653
;
I managed to find the file format reference somewhere, the important info here is the knot indexes (16 0 0 0 1 2 3 4 5 6 7 8 9 10 11 11 11) and the coordinates (all lines containing three numbers).
But, I still have no idea how to recreate the curve. I googled a lot for nurbscurves, bsplines etc, but could not successfully match the result in Maya with any code I could find.
I've achieved this in 3dsmax by exporting the curve in Ascii format and parsing the text manually, does Maya have any such exporter?