How can I retrieve the transform information on a layer

Well examples show using a smartObject, not even sure what you mean by "Bitmap pixels are gone"???

There are problem with that script's function    getSmartObjectScale  getgetSmartObjectScaleSmartObjectScale getSmartObjectScale  getSmartObjectScale.

function getSmartObjectScale (layer) {
    if (layer.kind != LayerKind.SMARTOBJECT) {alert("layer is not smart object!"); return null;}
     var originalActiveLayer = app.activeDocument.activeLayer;
     app.activeDocument.activeLayer = layer;
     //获取智能对象当前尺寸
     var originalSize = getSmartObjectSize (layer);
    //进入智能对象编辑页面，获取智能对象原尺寸
    var idplacedLayerEditContents = stringIDToTypeID( "placedLayerEditContents" );
    var desc1900 = new ActionDescriptor();
    executeAction( idplacedLayerEditContents, desc1900, DialogModes.NO );//进入对象编辑页面
    //获取文档大小
    var width = app.activeDocument.width.value;
    var height = app.activeDocument.height.value;
    app.activeDocument.close (SaveOptions.DONOTSAVECHANGES);
    app.activeDocument.activeLayer = originalActiveLayer;
    
    return {"width": originalSize.width/width, "height": originalSize.height/height};
}

All smart object layers are not the same. There are different type of objects.  That script function opens the active layer object "placedLayerEditContents" that is a problem.  All object will not be opened by Photoshop.  A placed image file may not open in Photoshop.  My test document had a Placed RAW file when the script function open the object  I was then in ACR when I click OK the function closed the current document in Photoshop and there was no open Document in Photoshop.  Likewise with a vector smart object layer a placed .svg file the SVG was opend in Internet Eplorer on my machine and when I closed IE the function close the current document and nothing was open in Photoshop.

When my smart object layer was a placed Jpeg file the function  getSmartObjectScale   would only get the scale correct when the Documents DPI and the Jpeg same the same DPI.

I added thie alert to your script so you can see the scale isn not correct.

alert("scale " + scale.width + " " + scale.height + "\n"
     + "size " + size.width + " " + size.height + "\n"
     + "corners " + corners + "\n"
     + "bounds " + bounds + "\n"
     + "angle " + angle);

Here is a screen capture shows the Placed jpeg place transform in the tool option bar then I ran your script and then an other script like your that rounds values gets the scaling right and it works with all object types for it does not open the objects. Vector Smart Opbects have not size.  Devision by 0 is infinity so theat script shows infinity as yje scale value not what the Place transfom shows.  Photoshop must set some size for Places .svg and .ai files.  I was unable to figure out how Photoshop handled placed vector files like .svg and .ai files.

A Placed SVG file Follows

Here an Smart Object image layer with no rotation straight up portrait and not flipped,   then flipped horizontally, then flipped vertically, and then flipped  horizontally and  vertically.  Screen Capture shows the Smart object layers Transform setting in the tool option bar.  Also screen captures that show Information a script can retrieved using the action manager code r-bin posted for retrieving the objects dour corners and some of the additional smart object information available. By comparing the x,y corner points positions relative to each other in order one would be able to figure out if any flipping was done. However as shown in my previous append throwing in rotation may make it much harder rotation 90, 180, 270 may look like flipping or 180 may look lo 0 and 270 look like 90.

Re: Is there any way to retrieve angle and scale information of smart object?

Re: Photoshop Scripting- Smart objects - How can I get the changes made to a layer that is a smart object

I've made a script that somehow took the informations from the Smart Layer's transforms,

you can check this post: Need help cleaning up a script and adding loop, there is a reply there explaining what the script is doing, till now is the only way I found to get these values without reading the binary of the psd.

Sorry, here's some clarification.  If I use code found here How to extract layer rotation (transform) in jsx photoshop script? - Stack Overflow for retrieving the transform of the text layer "PixelSquid Diving Helmet" it will work.  What I'm trying to do is get the transform that's applied to the layer DivingHelmet.H03, basically the data that is available:

I'd like the information on the existing transformations applied to the object, not trying to apply a new transformation to it.

Thanks again,

Mark