How to clear the image printed?

[tramhao]

Firstly, thanks for your work and it provides very good display result in kitty.
I'm using it in my repo(https://github.com/tramhao/termusic) to display the album photo.
The display works without problems. However, i need to clear the printed image if the song doesn't have an album photo.
I cannot figure out how to do it.
Thanks so much.

[tramhao]

I solve it by sending control sequence to terminal directly

    pub fn clear_image(&mut self) {
        write!(self.context.backend_mut(), "\x1b_Ga=d\x1b\\").expect("error delete image");
        self.context
            .backend_mut()
            .flush()
            .expect("error flush delete image");
    }

[tramhao]

If this is the correct way, please close this issue. Thanks.

[atanunq]

Thank you for using viuer. This is a really good point, I think viuer could use a clear/delete_image method. I will leave this issue open as a reminder :)

[tramhao]

I met this problem again but for iterm2 protocol. I'm using same code to clear picture in iterm2, but not working. I'm using wezterm. Do you know if there is a way to clear image in iterm2? I didn't find related information in their website. Thanks so much.

[kyoheiu]

I faced the same problem: By using termion, for example, clearing the image goes like this:

for i in 0..terminal_row {
    print!("{}", cursor::Goto(BEGINNING_COLUMN, BEGINNING_ROW + i as u16));
    print!("{}", clear::UntilNewline);
}

Both cursor::Goto and clear::UntilNewline in termion write escape sequences. This works fine when using alacritty, which does not support sixel.
However, with kitty, the above code does not work.
Is there any solution to this, or do I miss something? Thanks.

[hasezoey]

As this is likely still necessary, only 1 protocol has a built-in way to clear the image: kitty. For the others it looks like the best option is to just print (space) over the area the image was at to clear it.

It might be worth to look at how yazi-adapter (license MIT) does protocol and image handling.
It has detect (for protocols / terminals), show image and erase image. Though it seems to be completely undocumented and only intended to be used by the yazi crates themself (also see sxyazi/yazi#3342).

[j4james]

For the others it looks like the best option is to just print (space) over the area the image was at to clear it.

For sixel, I think the most efficient way to clear an image is with a DECERA sequence, at least on terminals that support rectangular area operations (you can check for feature number 28 in the DA report).

Otherwise the next best thing would be to erase it row by row with a bunch of ECH sequences. That should be supported by all terminals. And if that doesn't work, then writing a bunch of spaces probably won't work any better.

[hasezoey]

clear an image is with a DECERA sequence
(you can check for feature number 28 in the DA report).

I cannot find feature number 28 or DECERA related things in vt100: vt510-rm/DA1, which place would you recommend to see all feature numbers?

[j4james]

You can find a list of most feature numbers in chapter 4 of the DEC STD 070 Video Systems Reference Manual. The rectangular area operations are required for devices conforming to level 4 or above, which is why it's not listed as an extension in the VT510 manual (the extension list is for optional features).

Technically any terminal reporting 64 or higher in the first parameter of the DA report should also support DECERA, but modern terminals tend to lie about their conformance level, so relying on that can be a bit risky.