pyviewer 1.6.0

Interactyive python viewers

PyViewer

Pyviewer is a python library for easily visualizing NumPy arrays and PyTorch tensors.

Components

single_image_viewer.py

A viewer for showing single fullscreen images or line plots without other UI elements. Runs in a separate process and remains interactive even if the main process is suspended (e.g. in a debugger). Great for interactively looking at intermediate values of complex ML/CG/CV pipelines.

Usage:

from pyviewer import single_image_viewer as siv
siv.draw(img_chw=np.random.randn(3,64,64))
siv.plot(np.sin(2*np.pi*np.linspace(0, 1, 10_000)))

toolbar_viewer.py

A viewer that shows ImGui UI elemets on the left, and a large image on the right. Runs in the main process, but supports visualizing torch tensors directly from GPU memory (unlike single_image_viewer).

Other features

• Bundles a custom build of PyImGui with plotting support (via ImPlot)
• Dynamically rescalable user interface
• Window resizing to integer multiple of content resolution
• Pan and zoom of the main image

Installation

pip install pyviewer

Usage

See examples/demo.py for a usage example.

API highlights

PannableArea::screen_to_uv_xform
Maps absolute screen coordinates (e.g. imgui.get_mouse_pos()) to transformed image UVs, useful for picking etc.

PannableArea::uv_to_screen_xform
Maps image UVs to absolute screen coordinates. Useful when combined with imgui's draw lists.

PannableArea::get_visible_box_image()
Returns the top-left and bottom-right UV coordinates of the currently visible image region.

PannableArea::get_hovered_uv_image()
Returns the image UVs that lie under the mouse cursor.

PannableArea::get_hovered_uv_canvas()
Returns the canvas UVs that lie under the mouse cursor. Differs from the image UVs in case of non-matching image and window aspect ratios.

from pyviewer.single_image_viewer import draw; draw(img_chw=...)
One-liner that opens a new viewer (unless already open) and draws the provided image. Runs in a separate process and thus works even when execution is halted by e.g. a debugger.