How to remove line sample?

Question

You can sample the pixels of an image in a line with the Sample Line option in UV/Image editor > Properties Region > Sample Line, then dragging a line across an image.

However, I can't figure out how to remove the line afterwards. (I can zoom out and sample a new line far away from the image so it is less distracting, but this can't be the right way to do it)

How to remove or hide the sample line?

Answer 1

Basically you have to re-initiate it and then cancel that operation. If you have a line you can just LMB on the button once to activate it then RMB on it again. You can also invoke the space-function search menu and search 'Sample Color' activate it and hit ESC to cancel it.

Answer 2

Click the Sample Line button again, then RMB to cancel - and the previous line will be gone.

If you want a button to directly remove it, edit the space_image.py script like shown below:

class IMAGE_PT_sample_line(Panel):
    bl_space_type = 'IMAGE_EDITOR'
    bl_region_type = 'PREVIEW'
    bl_label = "Sample Line"

    @classmethod
    def poll(cls, context):
        sima = context.space_data
        return (sima and sima.image)

    def draw(self, context):
        layout = self.layout

        sima = context.space_data
        hist = sima.sample_histogram

        # Add a remove button for sample line
        split = layout.split(0.9, align=True)
        split.operator("image.sample_line")
        sub = layout.row()
        sub.operator_context = 'EXEC_DEFAULT'
        split.operator("image.sample_line", icon='X', text="")

        layout.template_histogram(sima, "sample_histogram")
        row = layout.row(align=True)
        row.prop(hist, "mode", expand=True)
        row.prop(hist, "show_line", text="")