I need to convert images for object detection. I start with svg images with multiple polygons. Example:
<svg ...>
<rect width = "100%" height = "100%" fill = "rgb(0,0,0)" />
<polygon points="..." fill="rgb(221,221,221)" fill-opacity="1.0" />
<polygon points="..." fill="rgb(100,100,100)" fill-opacity="0.5" />
</svg>
The result is a black background, object A having color rgb(221,221,221), object B having color rgb(50,50,50), and anywhere the two objects overlap rgb(160,160,160). The detection algorithm (cannot be modified) determines objects by their pixel values.
I have successfully converted from svg to png using inkscape, svgr-convert, or ImageMagikk. However the edges of these png images are always blurry which in interfering with my object detection.
Is there some way to convert having crisp edges? This image shows the conversion adding blurred pixels with incorrect values. I have zoomed into an edge to make it obvious.
edit: full image example
<svg viewBox="17.874 6.66874 74.0131 70.817" xmlns="http://www.w3.org/2000/svg">
<rect width = "100%" height = "100%" fill="black" fill-opacity="1.000000" stroke="black" stroke-opacity="1.000000" stroke-width ="0.000000"/>
<polygon points="66.499391,34.862972 35.730400,51.495089 68.667463,64.499553 " fill="rgb(221,221,221)" fill-opacity="1.000000" />
<polygon points="47.613765,49.254424 23.219703,52.458598 47.246912,50.965952 48.078815,51.599703 49.620943,52.471096 62.516253,65.471290 65.077318,43.877861 51.086443,12.014429 34.861708,20.532821 " fill="rgb(100,100,100)" fill-opacity="0.500000" />
</svg>
Add the attribute in the <svg> element ( it's inherited by all child elements)
shape-rendering="crispEdges"
While from my short test Inkscape seems not to honor that, rsvg-convert does. For your Imagemagick setup, you should make sure it delegates to librsvg, not Inkscape.
What you need to do is increase the density when reading your SVG file. You can either increase the density by some factor and save that result or you can increase the density by the factor and then resize by the inverse factor. The default density for SVG is 96 dpi. So in Imagemagick 6 the basic command would be:
convert test.svg test.png
which is the same as
convert -density 96 test.svg test1.png
Now you can increase the density by 4 to 384.
convert -density 384 test.svg test2.png
or for larger images with line drawings that you need to preserve at the original resolution, you can resize down by 1/4 or 25%
convert -density 384 test.svg -resize 25% test3.png
For Imagemagick 7, change convert to magick.
ADDITION:
Here is a version enlarged using density 1200, which will look smooth unless you zoom beyond the full resolution.
convert -density 1200 test.svg test4.png
Related
I'm referencing an svg file's content from my html, like this:
<svg id='container' width="19" height="19">
<use href="../svg.svg#path"/>
</svg>
svg.svg
<svg
id="home"
width="19"
height="19"
viewBox="0 0 19 19"
xmlns="http://www.w3.org/2000/svg">
<path id='path' fill-rule="evenodd" clip-rule="evenodd" d="M6.10156 2.31433C4.85892 2.31433
3.85156 3.32169 3.85156 4.56433V7.27979L5.21733 6.15722C5.88058 5.61207 6.84134 5.62857 7.48549
6.19616L11.5046 9.7376C11.8811 10.0694 12.0971 10.547 12.0976 11.0489L12.1032 16.8638H14.6256C15.8682
16.8638 16.8756 15.8565 16.8756 14.6138V4.56433C16.8756 3.32169 15.8682 2.31433 14.6256 2.31433H6.10156ZM2.35156
4.56433V8.51269L0.879033 9.72301C0.474603 10.0554 0.240234 10.5514 0.240234 11.0749L0.240249
16.6071C0.240252 17.5731 1.02297 18.3564 1.98897 18.3571L12.1047 18.3645L12.1047 18.3638H14.6256C16.6966
18.3638 18.3756 16.6849 18.3756 14.6138V4.56433C18.3756 2.49326 16.6966 0.814331 14.6256 0.814331H6.10156C4.03049
0.814331 2.35156 2.49326 2.35156 4.56433ZM6.49381 7.32159C6.40179 7.2405 6.26454 7.23814 6.16979 7.31602L1.83149 10.8818C1.77372 10.9293 1.74023 11.0002 1.74023 11.0749L1.74025 16.6071C1.74025 16.7451 1.85207 16.857 1.99007 16.8571L5.42188 16.8596V14.1996C5.42188 13.7854 5.75766 13.4496 6.17188 13.4496C6.58609 13.4496 6.92188 13.7854 6.92188 14.1996V16.8607L10.6032 16.8634L10.5976 11.0503C10.5975 10.9786 10.5667 10.9104 10.5129 10.863L6.49381 7.32159Z" />
</svg>
Question is:
Why do I need to set width and height in container? If I fail to do so, container takes up 150px by 300px.
How could I just make container automatically shrink to fit home's dimensions?
Thanks
The HTML spec says that if the size of any "replaced element" (that's things like <svg>, <canvas>, <object> etc) is not specified, then its size should default to 300px x 150px.
The <use> points to a <path>, rather than a whole SVG image, so it's size is indeterminate.
Given your use case, you cannot.
I'm using this to select the color i'm going to paint my rectangle, and with rgb its working.
style = "fill:rgb(144,0,0)"
Now if I try hsl no matter which value I set, it will always be black.
style = "hsl(28, 87%, 67%)"
Whole page code:
<svg width='200.000' height='200.00' xmlns='http://www.w3.org/2000/svg'>
<rect x='10.000' y='10.000' width='50.00' height='50.00' style='hsl(28, 87%, 67%)' />
<rect x='70.000' y='10.000' width='50.00' height='50.00' style='hsl(28, 87%, 67%)' />
</svg>
I am trying to create a half filled circle with d3.js to be like this.
I didn't find any example of how to do it.
How can this be done with d3.js?
Yes, you can do that with an SVG gradient. All you have to do is define it and then use it as fill for the circle.
var grad = svg.append("defs").append("linearGradient").attr("id", "grad")
.attr("x1", "0%").attr("x2", "0%").attr("y1", "100%").attr("y2", "0%");
grad.append("stop").attr("offset", "50%").style("stop-color", "lightblue");
grad.append("stop").attr("offset", "50%").style("stop-color", "white");
svg.append("circle")
.attr("fill", "url(#grad)");
JSfiddle here.
You may not even require d3 for this simple task. You may use this simple technique, Using Clippath on a circle, I have written it in details in my blog http://anilmaharjan.com.np/blog/2013/11/create-filled-circle-to-visualize-data-using-svg
Use Two circles one above another in a tag.
Fill one with the color you wish and another with white or may be your background color just to make it look like its empty in there.
Then clip the later one using with rectangle in it, assign radius few pixel less than the earlier circle.
Place clip path at the top left .. assign width equal to the diameter of the circle and height will be defined by your data.
The data will act reversible to the filling so you may subtract the actual data from your max. EG: if data is 20/100 do 100-20 so u ll get 80 in this way the empty part will be 80 and filled will be 20.
You may switch between height or width to switch between vertical or horizontal filling axis.
The HTML should look like this.
<svg height="200"> <a transform="translate(100,100)">
<g>
<circle fill="#f60" r="50"></circle>
</g>
<g>
<clippath id="g-clip">
<rect height="50" id="g-clip-rect" width="100" x="-50" y="-50">
</rect>
</clippath>
<circle clip-path="url(#g-clip)" fill="#fff" r="47"></circle>
</g>
</a>
</svg>
I have created a jsfiddle to illustrate this at: http://jsfiddle.net/neqeT/2/
create a div having id name id_cirlce and paste this code inside script tag
<div id="id_circle"></div>
<script>
var svg = d3.select("#id_circle")
.append("svg")
.attr("width",250)
.attr("height",250);
var grad = svg.append("defs")
.append("linearGradient").attr("id", "grad")
.attr("x1", "0%").attr("x2", "0%").attr("y1", "100%").attr("y2", "0%");
grad.append("stop").attr("offset", "50%").style("stop-color", "lightblue");
grad.append("stop").attr("offset", "50%").style("stop-color", "white");
svg.append("circle")
.attr("r",50)
.attr("cx",60)
.attr("cy",60)
.style("stroke","black")
.style("fill","url(#grad)");
</script>
Is there a way to use em as unit for SVG translations? As in
<rect height="10em" width="10em" transform="translate(0em, 10em)"
style="fill:none;stroke-width:3;stroke:black/>
The rectangle does not translate in Firefox, unless I remove the em as unit.
You can sort of do this if you wrap the element(s) you want to translate in a new coordinate system:
<svg>
<svg width="1em" height="1em" overflow="visible" viewBox="0 0 1 1">
<rect height="10" width="10" transform="translate(0, 10)" .../>
</svg>
</svg>
Another option if you only need translations and use elements that have x and y attributes (or equivalent) is to use those instead, like this:
<rect x="0" y="10em" height="10em" width="10em"
style="fill:none;stroke-width:3;stroke:black/>
A new specification for transforms in CSS/SVG is currently being worked on, and it will indeed allow units in translations, see here.
Unfortunately, not;
The specs explicitly allow for user units - that correspond to CSS units and default to pixel units when otherwise not specified - to be applied for coordinates, while translations are meant to be used with floating point numbers exclusively as defined by the SVGMatrix interface.
Another thing you could do if you're creating the rect with javascript is retrieve the font size of a parent element and convert the em value to px.
Using jQuery:
var one_em = +$("#parent").css("font-size").replace("px", "");
$("#parent").append("<rect transform=translate(0," + (10*one_em) + ") .../>")
on my website i allow users to create pictures with line of text they specify drawn on the picture
currently i use for that imagemagick convert - i specify svg template and let convert do the rest
here is part of code which is responsible for outputting text in the picture
<text text-anchor="middle" x="50%%" y="%s"
font-family="Times New Roman" font-size="55"
style="fill:rgb(255,255,255);">
%s
</text>
my problem is that if user provides very long strings, the text doesn't fit in the image.
i'd like text to be resized automatically to smaller font if it doesn't fit the picture. is it possible to do with svg templates? if not, what could be other solutions
You could add a script within the SVG template which called when the SVG is loaded and uses getComputedTextLength() to resize the font. It's a bit of a hacky solution, but it seems to work.
Here's a quick example that draws a box and some text inside it. The text should be resized to always fit in the box no matter how long it is (up to point at least):
To call the code when the SVG is loaded include onload="int(evt)" in the SVG tag.
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="400" height="80"
onload="init(evt)">
Then the actual script:
<script type="text/ecmascript">
<![CDATA[
function init(evt)
{
if ( window.svgDocument == null )
{
svgDocument = evt.target.ownerDocument;
}
maximum_length = 300;
my_text = svgDocument.getElementById('text-to-resize');
for (var font_size=55; font_size>0; font_size--)
{
if(my_text.getComputedTextLength() < maximum_length){break;}
my_text.setAttributeNS(null, "font-size", font_size);
}
}
]]>
</script>
I just used a for loop to decrement the font-size until the text length is less than the maximum specified; I'm sure there's a better way to resize the text.
Finally the actual text and box:
<rect id="rect1" x="20" y="10" width="320" height="50" fill="white" stroke="black"/>
<text id="text-to-resize"
text-anchor="middle"
x="170" y="50"
font-family="Times New Roman" font-size="55">
whatever text
</text>
</svg>
If you change the text, the font-size should change so that it fits inside the box. You'll probably want to change the x- and y- values to correctly centre the text too.
solved by abandoning svg and doing everything with imagemagick convert and mvg template
here's the simplified script example in case anyone's pursuing something similar
script is putting an image and a title on the canvas. title is created with separate convert command, saved as temporary file and then put onto the canvas
#!/bin/sh
TEMPLATE="
push graphic-context
viewbox 0 0 600 600
affine 1 0 0 1 0.0 0.0
push graphic-context
fill 'rgb(0,0,0)'
rectangle 0,0 600,600
pop graphic-context
push graphic-context
image Over 38,38 338,338 '%s'
pop graphic-context
push graphic-context
image Over 36,400 529,55 '%s'
pop graphic-context
pop graphic-context
";
#1. creating label fitting specified proportions
#2. converting mvg template to jpeg image (and trimming it in process)
#3. removing temp file with label
convert -size 529x55 -background black -family "Times New Roman" -gravity center -fill white label:"$2" "tmp/$1title.jpg" && printf "$TEMPLATE" "images/$1.jpg" "tmp/$1title.jpg" | convert mvg:- -trim +repage -bordercolor black -border 36 "images/$1converted.jpg" && rm "tmp/$1title.jpg"
#script parameters: $1 is image id, $2 is title text