Mirroring images

[Cicorione]

Hi @pgundlach,

Happy new year! 🍾😁

I wonder if, for the next year, you could add an attribute mirror for the image tag, e.g.: mirror="vertical/horizontal" or mirror="x-axis/y-axis" ; meanwhile I am trying with the transformation matrix and, as last resort, just flipping the images... 😓

See you next year! 😇

[pgundlach]

Horizontal mirroring:

<Layout xmlns="urn:speedata.de:2009/publisher/en"
    xmlns:sd="urn:speedata:2009/publisher/functions/en">

    <Record element="data">
        <PlaceObject>
            <Image width="3cm" file="ocean.pdf" />
        </PlaceObject>
        <PlaceObject>
            <Transformation matrix="-1 0 0 1 0 0">
                <Image width="3cm" file="ocean.pdf" />
            </Transformation>
        </PlaceObject>
    </Record>
</Layout>

Vertical mirroring (not quite what I expected)

<Layout xmlns="urn:speedata.de:2009/publisher/en"
    xmlns:sd="urn:speedata:2009/publisher/functions/en">

    <Record element="data">
        <PlaceObject>
            <Image width="3cm" file="ocean.pdf" />
        </PlaceObject>
        <PlaceObject frame="solid" framecolor="green">
            <Transformation matrix="1 0 0 -1 0 0">
                <Image width="3cm" file="ocean.pdf" />
            </Transformation>
        </PlaceObject>
    </Record>
</Layout>

I need to look into what happens with vertical mirroring

[Cicorione]

Regarding this:

<Transformation matrix="-1 0 0 1 0 0">

This is the first thing I tried, but the background wasn't visible on the page, the background measure the full page, thus I think it was wrong...

But now that you showed me this I do believe that it mirrored from coordinate x=0 and not from its center, so perhaps the background landed outside the page, that is why I couldn't see it... 🤔

[pgundlach]

Happy new year BTW!

[pgundlach]

To add: this is not my solution, just a thought. I am still thinking about a good interface.

I am currently thinking about something like this:

<Transformation mirror-h="yes" mirror-v="yes">
        <Image width="3cm" file="ocean.pdf" />
</Transformation>

[Cicorione]

I am not wise like you, but I do prefer succinct attribute; what about with an attribute with two values:

• mirror="yes,yes"
• mirror="1,1"

Also, wouldn't it be better as attribute of Image rather than Transformation? Image already has rotate as attribute, rotate and mirror are complimentary.

Thanks!

[pgundlach]

You are right with the succinct attributes. Perhaps something like "horizontal", "vertical" and "both" could be valid options? And naming the attribute: should it be 'mirror' or 'flip'? Or do you have a better suggestion?

The advantage of having the mirroring with <Transformation> is that you a mirror any object, not only images. The rotate attribute is somewhat special as it uses PDF operators that apply to images only.

It would not harm to have a mirroring option on both (<Image> and <Transformation>)

I still need to check if clipping etc. needs special considerations.

[Cicorione]

I did a quick research and both Illustrator and Inkscape call it FLIP, so I guess this is the common used name.

I agree with you that having all the "transformations" in one place is more predictable and consistent than having in two places, this avoids to have situation where you are applying two transformations even though your image looks correctly oriented.

[pgundlach]

Just a note for me...

<Layout xmlns="urn:speedata.de:2009/publisher/en"
    xmlns:sd="urn:speedata:2009/publisher/functions/en">
    <Pageformat height="20cm" width="7cm"></Pageformat>

    <Record element="data">
        <PlaceObject>
            <Textblock>
                <Paragraph>
                    <Value>Original:</Value>
                </Paragraph>
            </Textblock>
        </PlaceObject>
        <PlaceObject>
            <Image width="3cm" file="ocean.pdf" />
        </PlaceObject>
        <PlaceObject>
            <Textblock>
                <Paragraph>
                    <Value>Mirror vertical:</Value>
                </Paragraph>
            </Textblock>
        </PlaceObject>
        <PlaceObject frame="solid" framecolor="green">
            <Transformation mirror-y="yes">
                <Image width="3cm" file="ocean.pdf" />
            </Transformation>
        </PlaceObject>
        <PlaceObject>
            <Textblock>
                <Paragraph>
                    <Value>Mirror horizontal:</Value>
                </Paragraph>
            </Textblock>
        </PlaceObject>
        <PlaceObject frame="solid" framecolor="green">
            <Transformation mirror-x="yes">
                <Image width="3cm" file="ocean.pdf" />
            </Transformation>
        </PlaceObject>
        <NextRow />
        <PlaceObject>
            <Textblock>
                <Paragraph>
                    <Value>Mirror both axes:</Value>
                </Paragraph>
            </Textblock>
        </PlaceObject>
        <PlaceObject frame="solid" framecolor="green">
            <Transformation mirror-x="yes" mirror-y="yes">
                <Image width="3cm" file="ocean.pdf" />
            </Transformation>
        </PlaceObject>
    </Record>
</Layout>

[pgundlach]

Now implemented in 4.19.37.

[Cicorione]

Great!

Thank you very much!!!

[pgundlach]

https://doc.speedata.de/publisher/en/basics/outputtingobjects/#ch-outputtingobjectds-flipping