Offer warning before generating preview "quick-add steps" on very large images

[jywarren]

Uploading a big image (actually like any image from a smartphone camera 😂 📸 🤳 ) stalls out the sequencer because of the preview images. A few ideas:

1. we could not generate previews for the small steps if the image size is over a certain threshold, instead showing a message Generating previews for images this large may take a while. _Do it anyways_? so it can be overridden...
2. do we generate the preview resize once, then pass it to each preview step, or do we generate it multiple times from the original image?
3. make resizing images faster with optimization of the resize module?

Just thinking how we could smooth this out a bit!

[harshithpabbati]

@jywarren may be this is a solution for this https://sharp.pixelplumbing.com/en/stable/ and for even #961

[harshithpabbati]

Coverting larger images to friendly image formats. What do you say about it???

[harshkhandeparkar]

@jywarren I had mentioned about it in #955.
Also I think the images have to be downsclaes for the previews.

On my phone, the phone takes 15secs to even show the image in the load-image step and takes atleast 1.5 min to generate the previews. Then I actually saw the resolution, 3480x4610 and my phone is 3yrs old.

Without downscaling the imgs, the previews will just stop the page.

[jywarren]

Agreed! Ok, let's start by not running the preview generation on big images then? We can pursue other options once we do this. Are you interested in working on this one? Thanks!!!

…

On Mon, Apr 1, 2019, 12:38 AM Harsh Khandeparkar ***@***.***> wrote: @jywarren <https://github.com/jywarren> I had mentioned about it in #955 <#955>. Also I think the images *have to be* downsclaes for the previews. On my phone, the phone takes 15secs to even show the image in the load-image step and takes atleast 1.5 min to generate the previews. Then I actually saw the resolution, 3480x4610 and my phone is 3yrs old. Without downscaling the imgs, the previews will just stop the page. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#922 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABfJ5LQWEyxiyNUj6dKsYj-3hVI7-2lks5vcY0VgaJpZM4cEdFW> .

[aashna27]

I am pursuing this , adding this in my proposal.

[harshkhandeparkar]

@aashna27 please have a look at the discussion in #955. Try to adding an option to stop previews altogether, if you want/can/have time. Thanks.

[jywarren]

Noting for the preview refactor, we could add an intermediate sequencer object before passing to generatePreview:

image-sequencer/examples/lib/insertPreview.js

Lines 1 to 3 in 0eb3f26

	function generatePreview(previewStepName, customValues, path, selector) {
	var previewSequencer = ImageSequencer();

We could do it just before passing the image to this iterator:

image-sequencer/examples/lib/insertPreview.js

Lines 47 to 49 in 440c3e0

	Object.keys(previewSequencerSteps).forEach(function (step, index) {
	generatePreview(step, Object.values(previewSequencerSteps)[index], src, selector);
	});