tevclient   

Module for remote-controlling the tev image viewer. This module implements tev's IPC protocol, allowing you to control tev via a TCP connection. You can create, modify, reload, and close images as well as overlay vector graphics.

The initial version of this module was written by Tomáš Iser and contributed to tev.

Installation

pip install tevclient

Usage

Enter a context via the Ipc class (or an async context using IpcAsync), which will handle the connection to tev. Then instrument tev by calling the various methods of the context.

import tevclient

with tevclient.Ipc() as tev_ipc:
# or: async with tevclient.IpcAsync() as tev_ipc:

    # Open an image
    tev_ipc.open_image("path/to/image.png")
    # or: await tev_ipc.open_image("path/to/image.png")

    # Create a new image
    tev_ipc.create_image("My Image", width=800, height=600, channel_names=["R", "G", "B"])

    # Update the image with pixel data
    import numpy as np
    image_data = np.random.rand(600, 800, 3)  # Random RGB data
    tev_ipc.update_image("My Image", image_data, ["R", "G", "B"])

    # Close the image
    tev_ipc.close_image("My Image")

The following methods are available:

Operation	Function
open_image	Opens an image from a specified path on the machine tev is running on.
create_image	Creates a blank image with a specified name, size, and set of channels. If an image with the specified name already exists, it is overwritten.
update_image	Updates the pixels in a rectangular region.
close_image	Closes a specified image.
reload_image	Reloads an image from a specified path on the machine tev is running on.
update_vector_graphics	Draws vector graphics over a specified image.

Each method comes with type annotations and a docstring, so should be self-explanatory when used in an IDE.

Examples

More complete examples than the one above can be found in the examples/ directory of this repository. Below is an excerpt that showcases tilewise updating of an image and drawing vector graphics over it.

import time
import numpy as np
import tevclient

with tevclient.Ipc() as tev_ipc:
    # Create sample image in one go. The image will have RGB channels (displayed as one layer)
    # as well as a 'Bonus' channel (displayed as another layer)
    image_data = np.full((300, 200, 3), 1.0)
    image_data[40:61, :, 0] = 0.0
    image_data[:, 40:61, 1] = 0.0
    image_data[50:71, 50:71, 2] = 0.0

    bonus_data = image_data[:, :, 0] + image_data[:, :, 1] + image_data[:, :, 2]

    tev_ipc.create_image("Test image 1", width=200, height=300, channel_names=["R", "G", "B", "Bonus"])
    tev_ipc.update_image("Test image 1", image_data, ["R", "G", "B"])
    tev_ipc.update_image("Test image 1", bonus_data, ["Bonus"])

    # Create another image that will be populated over time
    RESOLUTION = 256
    TILE_SIZE = 64
    N_TILES = (RESOLUTION // TILE_SIZE) ** 2

    tev_ipc.create_image("Test image 2", width=RESOLUTION, height=RESOLUTION, channel_names=["R", "G", "B"])

    idx = 0
    for y in range(0, RESOLUTION, TILE_SIZE):
        for x in range(0, RESOLUTION, TILE_SIZE):
            tile = np.full((TILE_SIZE, TILE_SIZE, 3), idx / N_TILES)
            tev_ipc.update_image("Test image 2", tile, ["R", "G", "B"], x, y)

            # Display a rectangle where the tile was updated
            tev_ipc.update_vector_graphics(
                "Test image 2",
                [
                    tevclient.vg_begin_path(),
                    tevclient.vg_rect(x, y, TILE_SIZE, TILE_SIZE),
                    # Alternatively: draw rectangle manually
                    # tevclient.vg_move_to(x, y),
                    # tevclient.vg_line_to(x, y + TILE_SIZE),
                    # tevclient.vg_line_to(x + TILE_SIZE, y + TILE_SIZE),
                    # tevclient.vg_line_to(x + TILE_SIZE, y),
                    # tevclient.vg_close_path(),
                    tevclient.vg_stroke(),
                    # Draw tile index as string in bottom left corner
                    tevclient.vg_font_size(20, tevclient.ScaleKind.Relative),
                    tevclient.vg_text_align(tevclient.TextAlign.Left | tevclient.TextAlign.Baseline),
                    tevclient.vg_text(
                        x + 5,
                        y + TILE_SIZE - 5,
                        f"Tile {idx}",
                    ),
                ],
            )

            idx += 1
            time.sleep(0.1)

License

BSD 3-Claude; see LICENSE for details.