Pixel Map

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Felix
Posts: 72
Joined: Tue Oct 29, 2013 8:10 am

Pixel Map

Post by Felix » Tue Nov 12, 2013 8:23 am

Hi Pasi,

I have a question for pixel map representation.
In "IntensityGridSeries" chart, the value is shown at the corners of the grid.
As shown in the first image.
Chart IntensityGridSeries
Chart IntensityGridSeries
Chart with Grid and Nodes.jpg (202.44 KiB) Viewed 6240 times
In how it is in the pixel map, since the colored area is the same size as a grid.
As shown in the second image.
Chart Pixel Map
Chart Pixel Map
Chart Pixel Map.jpg (101.65 KiB) Viewed 6240 times
Then that's not a false color representation, or I understand that wrong?
What a value representing a pixel?
If it does not look as shown in the third picture?
Chart with the right Pixel Map
Chart with the right Pixel Map
Chart with the right Pixel.jpg (208.29 KiB) Viewed 6240 times

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ArctionPasi
Posts: 1366
Joined: Tue Mar 26, 2013 10:57 pm
Location: Finland

Re: Pixel Map

Post by ArctionPasi » Tue Nov 12, 2013 12:09 pm

The intensity points are grid nodes, corners of rectangles and eventually triangles. The PixelRendering style is different, and no color interpolation is made there. We have to render the series as pixel bitmap in the same X/Y range than without PixelRendering.

This is a 4x3 heatmap, with nodes and wireframe visible. 4 nodes in X dim, 3 nodes in Y dim.
4 x 3 heat map, interpolated
4 x 3 heat map, interpolated
heatmap4x3_wireframe.jpg (101.56 KiB) Viewed 6237 times

When setting this to show as PixelRendering style, it looks like this:
4x 3 heat map, PixelRendering
4x 3 heat map, PixelRendering
heatmap4x3_pixelrendering.jpg (85.1 KiB) Viewed 6237 times
4 rectangles horizontally, 3 rectangles vertically, in same range of 0..100 in both X and Y axis.

To make these rectangles to appear in center of each grid node, you must adjust the grid range a little bit.
cellWidth = (RangeMaxX - RangeMinX)/(SizeX-1)
cellHeight = (RangeMaxY - RangeMinY)/(SizeY-1)

RangeMinX = normalRangeMinX - cellWidth/2.
RangeMaxX = normalRangeMaxX + cellWidth/2.
RangeMinY = normalRangeMinY - cellHeight/2.
RangeMaxY = normalRangeMaxY + cellHeight/2.

Then the heat map shows as:
4 x 3 heat map, PixelRendering, ranges adjusted
4 x 3 heat map, PixelRendering, ranges adjusted
heatmap4x3_RangesAdjusted.jpg (73.3 KiB) Viewed 6237 times
Don't look at the colors, because they are taken from another random data set, but look at centers of the rectangles.

Did I understand the problem you tried to present correctly?
LightningChart Support Team, PT

Felix
Posts: 72
Joined: Tue Oct 29, 2013 8:10 am

Re: Pixel Map

Post by Felix » Thu Nov 14, 2013 12:20 pm

Thank you. :D