Getting an Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

[Ahmed-Sajjad]

I'm using the sejda-console and running the command pdftopng for a pdf
pdftopng -f /Desktop/ahmed.pdf -o /Desktop/images/ahmed -r 1000
and after that i'm getting the exception
Created output temporary buffer C:\Users\asajjad\AppData\Local\Temp\sejdaTmp6514550043266928511.tmp Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at java.awt.image.DataBufferInt.<init>(Unknown Source) at java.awt.image.Raster.createPackedRaster(Unknown Source) at java.awt.image.DirectColorModel.createCompatibleWritableRaster(Unknown Source) at java.awt.image.BufferedImage.<init>(Unknown Source) at org.sejda.sambox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1475) at org.sejda.sambox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1403) at org.sejda.sambox.rendering.PageDrawer.applySoftMaskToPaint(PageDrawer.java:527) at org.sejda.sambox.rendering.PageDrawer.getNonStrokingPaint(PageDrawer.java:630) at org.sejda.sambox.rendering.PageDrawer.fillPath(PageDrawer.java:699) at org.sejda.sambox.contentstream.operator.graphics.FillNonZeroRule.process(FillNonZeroRule.java:36) at org.sejda.sambox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:823) at org.sejda.sambox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:486) at org.sejda.sambox.contentstream.PDFStreamEngine.processTransparencyGroup(PDFStreamEngine.java:237) at org.sejda.sambox.rendering.PageDrawer.access$1600(PageDrawer.java:98) at org.sejda.sambox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1525) at org.sejda.sambox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1403) at org.sejda.sambox.rendering.PageDrawer.showTransparencyGroup(PageDrawer.java:1345) at org.sejda.sambox.contentstream.operator.graphics.DrawObject.process(DrawObject.java:66) at org.sejda.sambox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:823) at org.sejda.sambox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:486) at org.sejda.sambox.contentstream.PDFStreamEngine.processStream(PDFStreamEngine.java:467) at org.sejda.sambox.contentstream.PDFStreamEngine.processPage(PDFStreamEngine.java:154) at org.sejda.sambox.rendering.PageDrawer.drawPage(PageDrawer.java:204) at org.sejda.sambox.rendering.PDFRenderer.renderImage(PDFRenderer.java:172) at org.sejda.sambox.rendering.PDFRenderer.renderImageWithDPI(PDFRenderer.java:109) at org.sejda.impl.sambox.component.PDDocumentHandler.renderImage(PDDocumentHandler.java:360) at org.sejda.impl.sambox.PdfToMultipleImageTask.execute(PdfToMultipleImageTask.java:90) at org.sejda.impl.sambox.PdfToMultipleImageTask.execute(PdfToMultipleImageTask.java:52) at org.sejda.core.service.DefaultTaskExecutionService.actualExecution(DefaultTaskExecutionService.java:148) at org.sejda.core.service.DefaultTaskExecutionService.execute(DefaultTaskExecutionService.java:71) at org.sejda.core.service.DefaultTaskExecutionService.execute(DefaultTaskExecutionService.java:58) at org.sejda.cli.DefaultTaskExecutionAdapter.execute(DefaultTaskExecutionAdapter.java:92)

Could anyone help me out as to why is it happening? is it because of the resolution coz it works with smaller pdfs. or maybe because the pdf is heavy thats why its crashing.

More info:
=> I tried it on a 20 page pdf first, then this happened for another 3 page pdf.
=> I'm using the normal (free) version