How can I get the image display size?

[luckymore]

Attach (recommended) or Link to PDF file here:
https://arxiv.org/pdf/2404.01370.pdf

Configuration:

• Web browser and its version: chrome 123.0.6312.107 (x86_64)
• Operating system and its version: 13.6.3 (22G436)
• PDF.js version: '4.0.379'
• Is a browser extension: No

Steps to reproduce the problem:

1. Get the viewport with page.getViewport({ scale: 1 })

{
    "viewBox": [
        0,
        0,
        612,
        792
    ],
    "scale": 1,
    "rotation": 0,
    "offsetX": 0,
    "offsetY": 0,
    "transform": [
        1,
        0,
        0,
        -1,
        0,
        792
    ],
    "width": 612,
    "height": 792
}

2. Get the Image in page 2 with page.objs.get(id)

[
    {
        "width": 2000,
        "height": 2000,
        "kind": 2,
        "dataLen": 12000000,
        "ref": "203R"
    },
    {
        "width": 1749,
        "height": 1749,
        "kind": 2,
        "dataLen": 9177003,
        "ref": "204R"
    },
    {
        "width": 960,
        "height": 36,
        "kind": 2,
        "dataLen": 103680,
        "ref": "205R"
    }
]

What went wrong?

Why all the images size greater than page size?

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

### Tasks

[carlbrn]

Here the method I use. Although, I'm not sure 'transform' is always happening before 'paintImageXObject'. So far it has been the case with the PDFs I use.

Basically, if you iterate through the operator list you can catch the image 'transform' and use that.

type Transform = [number, number, number, number, number, number]

// Use the unit to convert numbers to inch if needed.
const unit = page.userUnit * 72

const opList = await page.getOperatorList()

let lastTransform: Transform | null = null

for (let i = 0; i < opList.fnArray.length; i++) {

	if (opList.fnArray[i] === pdfjsLib.OPS.transform) {
	    const args = opList.argsArray[i]
	    lastTransform = args as Transform
	}

	if (opList.fnArray[i] === pdfjsLib.OPS.paintImageXObject && lastTransform) {
		// here use the transform to get the size, you can also use it to get the position and polygon.
		const imageWidth = Math.abs(lastTransform[0])
		const imageHeight = Math.abs(lastTransform[3])

		const imageWidthInch = Math.abs(lastTransform[0]) / unit
		const imageHeightInch = Math.abs(lastTransform[3]) / unit
	}
}