I want to extent the image using vips. In PHP imagick it has method Imagick::extentImage. How can I achieve it with vips. I found this link but it's not giving output as I want
https://github.com/libvips/libvips/issues/857
How can I pass x and y coordinates like imagick.
extentImage( $width, $height, $x, $y )
Related
I'm trying to animate 2D vector with gnuplot. I want to show one line i.e, one vector at a time.
My Data Structure is as follows: They x,y,u,v
2.24448 0.270645 1.00 1.00
3.24448 0.270645 0.500 1.20
I'm able to create a static plot sing following command:
plot "datam.dat" using 1:2:3:4 with vectors filled head lw 3
Here is the output:
Here is my question: I would like to animate and show one row (i.e,) one vector at a time, how to accomplish this in GNU plot using GIF?
Thanks
Animated GIFs are created with set terminal gif animate. Check help gif for details.
Below is a simple example (tested with gnuplot 5.2). You have to make a new plot for each frame. So, put your plot command into a do for-loop. With every ::i::i you are plotting only the ith line (check help every). If you don't know the total number of lines of your datafile, do stats "YourFile.dat" and the variable STATS_records will tell you this number.
Code:
### animated graph with vectors
reset session
set term gif size 300,300 animate delay 12 loop 0 optimize
set output "AnimateVectors.gif"
# create some dummy data
set angle degrees
N = 60
set samples N
set table $Data
plot [0:360] '+' u (cos($1)):(sin($1)):(sin($1)):(cos($1)) w table
unset table
set xrange[-2.5:2.5]
set yrange[-2.5:2.5]
do for [i=0:N-1] {
plot $Data u 1:2:3:4 every ::i::i w vectors lw 2 lc rgb "red" notitle
}
set output
### end of code
Result:
Addition:
This would be the non-animated version, e.g. in a wxt-terminal.
Code:
### non-animated graph with vectors
reset session
set term wxt size 400,400
# create some dummy data
set angle degrees
N = 60
set samples N
set table $Data
plot [0:360] '+' u (cos($1)):(sin($1)):(sin($1)):(cos($1)) w table
unset table
set xrange[-2.5:2.5]
set yrange[-2.5:2.5]
plot $Data u 1:2:3:4 w vectors lw 1.5 lc rgb "red" notitle
### end of code
Result:
Addition2:
Do you maybe mean something like this? A "semi"-animated arrow? By the way, as you can see the arrow look quite different in gif and wxt terminal.
Code:
### "semi"-animated graph with vectors
reset session
set term gif size 300,300 animate delay 12 loop 0 optimize
set output "AnimateVectorsSemi.gif"
# create some dummy data
set angle degrees
N = 60
set samples N
set table $Data
plot [0:360] '+' u (cos($1)):(sin($1)):(sin($1)):(cos($1)) w table
unset table
set xrange[-2.5:2.5]
set yrange[-2.5:2.5]
do for [i=0:N-1] {
plot $Data u 1:2:3:4 every ::0::i w vectors lw 1.5 lc rgb "red" notitle
}
set output
### end of code
Result:
Like this:
Calculating coordinates looks not so good, maybe there is a better way?
This code works fine (), but it's complicated always calculate where to place index for each letter.
image = Image.new('I', (300, 100), "white").convert('RGBA')
font = ImageFont.truetype(font=r"C:\Windows\Fonts\Arial.ttf", size=39)
draw = ImageDraw.Draw(image, 'RGBA')
draw.text((10, 10), "P", fill="black", font=font, align="center")
font = ImageFont.truetype(font=r"C:\Windows\Fonts\Arial.ttf", size=20)
draw.text((25, 35), "2", fill="black", font=font, align="center")
image.save(output_folder + 'test.png')
One possibility for you might be to use ImageMagick which understands Pango Markup Language - which looks kind of like HTML.
So, at the command-line you could run this:
convert -background white pango:'<span size="49152">Formula: <b>2P<sub><small><small>2</small></small></sub>O<sub><small><small>5</small></small></sub></b></span>' formula.png
which produces this PNG file:
Change to -background none to write on a piece of transparent canvas if you want to preserve whatever is underneath the text in your original image.
You can also put all the markup in a separate text file, called say "pango.txt" like this:
<span size="49152">Formula: <b>2P<sub><small><small>2</small></small></sub>O<sub><small><small>5</small></small></sub></b></span>
and pass that into ImageMagick like this:
convert pango:#pango.txt result.png
You could shell out and do this using:
subprocess.call()
Then you can easily load the resultant image and composite/paste it in where you want it - that would take about 3 lines of Python that you could put in a function.
Here is a further example of an image generated with Pango by Anthony Thyssen so you can see some of the possibilities:
There is loads of further information on Pango by Anthony here.
Note that there are also Python bindings for ImageMagick but I am not very familiar with them, but that may be cleaner than shelling out.
Keywords: Pango, PIL, Pillow, Python, markup, subscript, superscript, formula, chemical formulae, ImageMagick, image, image processing, SGML, HTML.
You can also do this sort of thing using Mathtext in Matplotlib:
#!/usr/bin/env python3
import matplotlib.pyplot as plt
plt.axes([0.025, 0.025, 0.95, 0.95])
# Some formula with superscripts, subscripts, square roots, fractions and integrals
eq = r"$ 2P_2 O_5 + H^{2j}$"
size = 50
x,y = 0.5, 0.5
alpha = 1
params = {'mathtext.default': 'regular' }
plt.rcParams.update(params)
plt.text(x, y, eq, ha='center', va='center', color="#11557c", alpha=alpha,
transform=plt.gca().transAxes, fontsize=size, clip_on=True)
# Suppress ticks
plt.xticks(())
plt.yticks(())
# Save on transparent background
plt.savefig('result.png', transparent=True)
You can also save the output in a memory buffer (without going to disk) and then use that in your PIL-based image processing.
Note that I have explicitly named and assigned all the parameters (x, y, size and alpha) so you can play with them and that makes the code look longer and more complicated than it actually is.
Keywords: Python, PIL, Pillow, maths, mathematical symbols, formula with superscripts, subscripts, square roots, fractions and integrals.
I am trying to develop one python app. the app should print text in an a4 page and on that a4 sheet already there are 4 rectangle boxes, i have to put text in center allign format in each box. the image is attached as reference.sample image
i have written something like this using reportlab.
self.canvas = canvas.Canvas(name, pagesize=landscape(A4))
self.canvas.drawCentredString(x1,y1,"c1")
but i am not achieving my goal.
rlhelper has some useful functions which may be of assistance here.
If you can identify the mid-point x-coordinate of each box, the following function can work:
import rlhelper
simpleCentredstring('canvas', 'x', 'y', 'string', 'fontcolor', 'font (+weight)','fontsize')
Is it possible to change or replace output colors in Imagick adaptiveThresholdImage?
I use this code: http://phpimagick.com/Imagick/adaptiveThresholdImage
function adaptiveThresholdImage($imagePath, $width, $height, $adaptiveOffset)
{
$imagick = new \Imagick(realpath($imagePath));
$adaptiveOffsetQuantum = intval($adaptiveOffset * \Imagick::getQuantum());
$imagick->adaptiveThresholdImage($width, $height, $adaptiveOffsetQuantum);
header("Content-Type: image/jpg");
echo $imagick->getImageBlob();
}
I made a picture with PS, what I need via adaptiveThresholdImage:
what I need
Unfortunatelly I can't any informations from output formatting.
Regards
It appears that you want each pixel of the output image to be a at least a certain shade of gray, or the brighter color from the output of adaptiveThresholdImage.
Probably the easiest way to do that is add:
$imagick->evaluateimage(\Imagick::EVALUATE_MAX, 0.5);
To after the call to adaptiveThresholdImage.
I was working on following images to find lines and spots in these images. I am working with OpenCV, C++. I have tried HoughLineP, HoughLine, Contour and Canny methods but couldn't get the results. If someone can help or write a pseudo-code, I shall be grateful.
Thanks.
Image to detect line:
Image to detect spot:
Mmmmm - where did you get those awful images? Well, they were worth 2 minutes of effort... the spot is lighter than the rest, so if you divide the image into 100 rectangles and find the brightest ones, you will probably get it... I use ImageMagick here just at the command line - it is installed on most Linux distros and available for OSX and Windows:
convert noise.jpg -crop 10x10# -format "%[mean] %g\n" info: | sort -n
32123.3 640x416+384+291
32394.6 640x416+256+42
32442.2 640x416+320+125
32449.1 640x416+384+250
32459.6 640x416+192+374
32464.4 640x416+0+374
32486.5 640x416+448+125
32491.4 640x416+576+374
32493.7 640x416+576+333
32504.3 640x416+576+83
32520.9 640x416+576+0
32527 640x416+448+0
32621.8 640x416+384+333
32624.1 640x416+320+42
32631.3 640x416+192+333
32637.8 640x416+384+42
32643.4 640x416+512+0
32644.2 640x416+0+0
32652.6 640x416+384+83
32659.1 640x416+128+374
32660.4 640x416+320+208
32662.2 640x416+384+0
32668.5 640x416+256+208
32669.4 640x416+0+333
32676.7 640x416+256+250
32683.5 640x416+256+83
32699.7 640x416+0+208
32701.3 640x416+64+166
32704 640x416+576+208
32704 640x416+64+333
32707.5 640x416+512+208
32710.8 640x416+192+83
32729.8 640x416+320+83
32733.4 640x416+256+166
32735 640x416+576+250
32741 640x416+256+125
32745.4 640x416+0+166
32748.4 640x416+320+166
32751.4 640x416+512+166
32752.4 640x416+512+42
32755.1 640x416+384+208
32770.9 640x416+448+291
32776.8 640x416+128+166
32777.1 640x416+256+0
32795.8 640x416+512+125
32801.5 640x416+128+333
32803.3 640x416+192+125
32805.5 640x416+256+374
32809.6 640x416+448+166
32810 640x416+576+166
32822.2 640x416+0+291
32822.8 640x416+576+42
32826.8 640x416+320+333
32831.7 640x416+320+0
32834.8 640x416+192+42
32837.6 640x416+192+166
32843 640x416+384+125
32862 640x416+64+374
32865.8 640x416+0+42
32871.5 640x416+576+291
32872.5 640x416+0+83
32872.8 640x416+448+333
32873.6 640x416+320+291
32877.5 640x416+448+42
32880.5 640x416+64+208
32883.5 640x416+128+42
32883.9 640x416+192+208
32885.5 640x416+128+208
32889.2 640x416+256+333
32921 640x416+192+291
32923.3 640x416+64+291
32929.2 640x416+512+374
32935.4 640x416+192+250
32938.4 640x416+64+250
32943.5 640x416+448+374
32953.3 640x416+384+374
32954.7 640x416+320+374
32962 640x416+320+250
32966.9 640x416+448+83
32967.3 640x416+128+291
32968.3 640x416+0+250
32970.8 640x416+512+333
32974.5 640x416+64+0
32979.6 640x416+512+291
32983.6 640x416+256+291
32988.9 640x416+448+250
32993.3 640x416+576+125
33012.7 640x416+0+125
33057.3 640x416+512+250
33068.6 640x416+128+250
33102.9 640x416+64+42
33126.1 640x416+512+83
33127.9 640x416+384+166
33139.2 640x416+192+0
33141.4 640x416+64+83
33142.3 640x416+64+125
33181.5 640x416+448+208
33190.8 640x416+128+0
34693 640x416+128+125
36178.3 640x416+128+83
The last 2 rectangles are the brightest, so if I box them in in red and blue you can see what it has found:
convert noise.jpg -fill none -stroke red -draw "rectangle 128,83 192,123" -stroke blue -draw "rectangle 128,125 192,168" result.png
Alternatively, you could create a new image in which each pixel is the mean of the 50x50 square of surrounding pixels in the original image, like this:
convert noise.jpg -virtual-pixel edge -statistic mean 50x50 -auto-level result.png
Of course, you can also threshold that:
convert noise.jpg -virtual-pixel edge -statistic mean 50x50 -auto-level -threshold 80% result.png
As regards the lines, I want to use some type of mode to detect the frequently occurring values within small areas but as the colours vary, I need to reduce the palette of colours to find things that are just similarly coloured so I would go with an approach something like this which reduces the colours then calculates the mode:
convert noise2.jpg -colors 8 -statistic mode 8x8 result.jpg
It needs refinement, but you get the idea hopefully.
Alternatively, you could calculate a new image wherein each pixel is the standard deviation of the surrounding 3x3 pixels in the original image and then look for the ones where this value is lowest - i.e. where the image is darkest which corresponds to areas in the input image where there is least variation in the pixel colours:
convert noise2.png -statistic standarddeviation 3x3 -auto-level result.png