We recently migrated from FOP 2.1 to FOP 2.6 and witnessed a change in PNG output quality. In our application fop is used with antialiasing OFF and in fop2.1 ( +batik 1.8) the text output is rendered nicely with no antialiasing .
But after we upgraded to FOP 2.6, PNG output is generated with antialiasing, without considering the fop.xconf setting or the text-rendering settings.

FOP 2.1 - Batik 1.8 output

FOP 2.6 - Batik 1.14 output

I tried various options by setting different text-rendering values but not able to get the same quality any more. I tried different versions of Batik lib and it seems that this change is seen from v1.9 onwards. Seems like batik is ignoring anti-aliasing OFF configuration from the fop.xconf .

fop.xconf

<?xml version="1.0"?>
<fop version="1.0">
<complex-scripts disabled="false"/>
    <renderers>
        <renderer mime="image/png">
            <color-mode>rgb</color-mode>
            <transparent-page-background>false</transparent-page-background>
            <background-color>white</background-color>
            <anti-aliasing>false</anti-aliasing>
            <rendering>false</rendering>
             <fonts>
            
            </fonts>
        </renderer>
        
    </renderers>
</fop>

---

Sample XSL

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.1" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" exclude-result-prefixes="fo">
    <xsl:output method="xml" version="1.0" omit-xml-declaration="no" indent="yes"/>
    <xsl:param name="versionParam" select="'1.0'"/> 
    <xsl:template match="articles[@page=1]">
        <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
            <fo:layout-master-set>
                <fo:simple-page-master master-name="simpleA4" page-height="168px" page-width="384px">
                    <fo:region-body /> <!-- background-color="#FFFF00" -->
                </fo:simple-page-master>
            </fo:layout-master-set>
            <fo:page-sequence master-reference="simpleA4">
                <fo:flow flow-name="xsl-region-body">
            
                
                <!-- Temporarily Unavailable -->
                <fo:block-container position="absolute" overflow="visible">
                    <fo:block>
                        <fo:instream-foreign-object xmlns:svg="http://www.w3.org/2000/svg">
                               <svg xmlns="http://www.w3.org/2000/svg" height="100" width="240" viewport="10 10 290 200">
                                    <text x="150" y="20" fill="black" text-anchor="start"  font-size="22pt" text-rendering="optimizeLegibility">STWOA</text>
                                </svg>
                        </fo:instream-foreign-object>                       
                    </fo:block>
                </fo:block-container>
                
            
                
                </fo:flow>
            </fo:page-sequence>
        </fo:root>
    </xsl:template>
</xsl:stylesheet>

Any help or hints would be highly appreciated !