Here is PC Windows java converter to fit the A4 300DPI Gray picture to DR1000
The A4 JPG has 2479x3508 pixels, show area is full screen excluding toolbox area.
Purpose cropping top and bottom blank margin with A4 300 dpi JPEG PDFCreater output,
and increase font bold, let it black.
I have some pdf file which has worst contrast, and the font glyph too thin to see.
So, the idea is
a) crop the blank margin to fit the screen, to get large view.
b) Image processing to enhance font darkness, let them deep dark.
Here, I use the gray Dilation filter to thick Font glyph. then the DR1000S will read it as Bold font. (Maybe, here is one idea for adjusting contrast/brightness


)
You can not change font attribute in PDF, but now we can do it in JPEG.
c) Batch processing file name which PDFCreater print with Prefix Filename, auto counting.
This does not have good document, please run in Cmd shell and with Big heap. You should install the JRE to run it.
CropDilation FileInputPrefix OutputPrefix PicCount [topy downy [DC contrast brightness]]
ex.
Java -Xms128m -Xmx512m CropDilation Page Out 10 254 3254
Convert from Page1.jpg~page10.jpg
Output Out0001.jpg~Out0010.jpg
Crop top 254 pixels scanlines.
and bottom crop from 3254 to height.
Width will keep about 2500 relative to 3000 to fit the DR1000.
Here is the class and Source attached.

Sorry! it has bug with croping left/right margin , I fixed it.
and add DC subtraction
Gray= (Pixel value - DC ) * contrast + Brightness