I wrote a program that periodically outputs KML files. These files contain a grid of polygons, always with the same spatial coverage. I want to use the polygon's fill color to represent a data values for each grid cell. I know how to set the fill color of the polygon with the Style tag. Is it possible to change to polygons color over time using the TimeStamp or TimeInterval? If not, is there a way to hide an "old" polygon and draw a "new" polygon at the same location, but with a different color? Is there a better way to represent a grid that has data value for each cell, like a Ground Overlay?
For changing the polygon color, you need to use 3rd party kml parsers like geoxml3.
see this,
changing the color of Polygons from KML rendered using geoxml3 on mouseover
Related
In meshlab, If I select a vertex and color it with red (per vertex color function), the result becomes
Red is too dispersed.
What I want is just : (image below was edited by photoshop):
How can I do it ?
On triangular meshes, when the color is defined in a per-vertex way, the colors are linearly interpolated across each triangle, so the result is precisely the expected one.
If you need just a way of looking at a few vertices, just enable the visualization of selected vertices and select them.
On the other hand, if you just need to reduce the color's spread, refine the mesh so that the underlying triangles are smaller, and the color is interpolated across a smaller area.
You can get something quite similar to your desired behavior.
The color dispersion is due to Gouraud shading. You can disable it clicking in the tab of face render options and change color button from "vertex" to "face" or "user defined"
To render vertex as "balls with color"
Click on the tab of vertex and choose the option Dot Decorator (1)
Change the size of dots with the Point Size Bar (2)
Let the color buttons in "mesh", not "user defined"
In MS Excel, I applied conditional formatting to a cell A1 so that it's color changes from blue at value 0 and red at value 100. I copied that cell and pasted it as linked picture(I) specially.(Paste Special). The color of the rectangle picture now changes if value in original cell is changed. The problem is, the shape is only rectangular, it can be converted into square and diamond shape at best.If same rectangle can be transformed into different shapes(maybe by adding extra anchor on rectangle shape), a heat map can be created easily. Please share your insights about this thing if there is a way.
Following pictures may help understand the problem:
[Example][1]
If you want a heat map, please consider using a CHART not gazillions of picture objects, colored/placed/rotated/etc to ... mimic a chart.
First, google anything about "surface chart" in Excel, see how it looks in Excel, whatever. Just see it and think about it so you can compare it to your current approach.
You will observe some things, like:
it's 3D
it has just a few layers/colors
etc.
But really, all of them can be solved. Probably easier than your current approach.
you can easily turn off both axes and you can rotate it so the camera is totally straight top-down - then it looks flat as paper and noone can see it as 3D anymore
you can add more layers, you can set each of them to specific colors
etc.
Some resources:
multiple colors in surface chart
how to change rotation of 3d chart
geesh, I just found even a whole article/tutorial dedicated to creating heat map charts.
Please, read that last link and I'm pretty sure you will want to use that approach instead of doing picture puzzles.
Is there a dataset that maps each of the ~16M RGB or hex color values to a general color family/category - e.g. red, purple, orange, beige, brown, etc. - that I could access programmatically or load into a database or JSON document to cross-refence the color codes against? The use case is to classify the results of PIL color detection of swatch files into a small set of color pickers for a shopping site. It would also work if the mapping is a bit more granular, say 100-200 categories, since it would be easy enough to map those to my target 10-15 myself. I have some knowledge of kNN classification and will work with that if I have to, but it would be so much easier to use a static mapping if one already exists.
You can use a table such as the one in X11
http://www.astrouw.edu.pl/~jskowron/colors-x11/rgb.html
In order to find color proximity, it's best to transform the colors to Lab color space first, so that euclidean distances have more meaning, and then nearest neighbor would give good results.
You could convert from RGB to CIE Lab color space wherein Euclidian distance between two color selections is perceptually more meaningful. Here is the link to all relevant color space transformation formulae used in OpenCV's color conversion method (cvtColor): http://docs.opencv.org/modules/imgproc/doc/miscellaneous_transformations.html
Since your use case is to compare two swatches, I would advise you to use texture descriptors (http://www.robots.ox.ac.uk/~vgg/research/texclass/with.html) in addition to color information for better results.
Following the provided example I built a function that draws a box plot to a jQuery accordion tab, which has a certain fixed height & width. The amount of distinct categories varies greatly depending on the incoming data. Currently I'd like to achieve the following in the plotting:
1) Add axes and display labels, like in this picture
2) Always fit the boxes to container width and height. Currently I see that if there are too many categories, some of them end on the second row, ensuring they're not fully seen. In the picture, the div contains 7 boxes but only 4 fit on one row:
The question is how can these two be implemented? I couldn't even figure out a way to reliably reduce the padding between the boxes without eating into the side numbers on the boxes.
I adopted the original d3.js example to include axes:
http://bl.ocks.org/jensgrubert/7789216
Instead of using individual svg elements as in Mike's implementation, here all boxplots are rendered with in one root element. This makes it easy to add axes.
Best,
Jens
For the time being I'm using a hack found at Highcharts forum (jsfiddle here). There's also a box plot implementation made with Raphael.js that looks cool (github, example)
How does dribble's color search work? It's not like other search by color features. What I can't figure out is how they can have search parameters for color variance and color minimum without storing a row for every individual color in an image (which I suppose is possible).
Colors are usually extracted from the image using a histogram computing the density of the colors. Once, you have the top 5/10/15 colors from the image, performing a search is matching the given color against these extracted colors.
To match a given color against other, various techniques are available such as minimizing the euclidean distance between the two colors. More on such techniques can be read at http://en.wikipedia.org/wiki/Color_quantization
Similar strategy is discussed in the blog entry http://mattmueller.me/blog/creating-piximilar-image-search-by-color