How to Display Custom Images in Tensorboard (e.g. Matplotlib Plots)?

Question

The Image Dashboard section of the Tensorboard ReadMe says:

Since the image dashboard supports arbitrary pngs, you can use this to embed custom visual

Answer 1

This intends to complete Andrzej Pronobis' answer. Following closely his nice post, I set up this minimal working example:

    plt.figure()
    plt.plot([1, 2])
    plt.title("test")
    buf = io.BytesIO()
    plt.savefig(buf, format='png')
    buf.seek(0)
    image = tf.image.decode_png(buf.getvalue(), channels=4)
    image = tf.expand_dims(image, 0)
    summary = tf.summary.image("test", image, max_outputs=1)
    writer.add_summary(summary, step)

Where writer is an instance of tf.summary.FileWriter. This gave me the following error: AttributeError: 'Tensor' object has no attribute 'value' For which this github post had the solution: the summary has to be evaluated (converted into a string) before being added to the writer. So the working code for me remained as follows (simply add the .eval() call in the last line):

    plt.figure()
    plt.plot([1, 2])
    plt.title("test")
    buf = io.BytesIO()
    plt.savefig(buf, format='png')
    buf.seek(0)
    image = tf.image.decode_png(buf.getvalue(), channels=4)
    image = tf.expand_dims(image, 0)
    summary = tf.summary.image("test", image, max_outputs=1)
    writer.add_summary(summary.eval(), step)

This could be short enough to be a comment on his answer, but these can be easily overlooked (and I may be doing something else different too), so here it is, hope it helps!