image_origin_anchor

An interactive explorer for image anchor and origin properties.

The anchor property can shift the image vertically or horizontally.

The origin property flip the image vertically or horizontally.

Details

Bokeh APIs:

figure.image_rgba

Keywords:

image, anchor, origin

import numpy as np

from bokeh.core.enums import Anchor, ImageOrigin
from bokeh.models import ColumnDataSource, Select
from bokeh.palettes import Sunset4
from bokeh.plotting import column, figure, show

Sunset4_RGBA = [[0xff9a4b36, 0xffe5d2a5], [0xff72c0fd, 0xff2600a5]]
img = np.array(Sunset4_RGBA, dtype=np.uint32)

p = figure(
    title="Different anchors and origins for image placed at coordinates (0, 0)",
    tools="", toolbar_location=None,
    x_range=(-10, 10), y_range=(-10, 10),
    background_fill_color="#efefef"
)
r = p.image_rgba(image=[img], x=0, y=0, dw=8.5, dh=8.5)
p.circle(0, 0, size=12, fill_color="black", line_color="white", line_width=3)

# a legend to identify the image pixel i, j coordinates
source = ColumnDataSource(data=dict(
    color=Sunset4,
    coord=["img[0,0]", "img[0,1]", "img[1,0]", "img[1,1]"],
))
p.square(0, 0, color="color", legend_group="coord", source=source, visible=False)
p.legend.location = "bottom_center"
p.legend.orientation = "horizontal"
p.legend.glyph_height = 30
p.legend.glyph_width = 30
p.legend.padding = 3
p.legend.margin = 5
p.legend.label_standoff = 0
p.legend.spacing = 25
p.legend.background_fill_color = None
p.legend.border_line_color = None

anchor = Select(title="anchor", options=list(Anchor), value=r.glyph.anchor)
anchor.js_link("value", r.glyph, "anchor")

origin = Select(title="origin", options=list(ImageOrigin), value=r.glyph.origin)
origin.js_link("value", r.glyph, "origin")

show(column(p, anchor, origin))