Is it possible to find all images below 300dpi in a document?

Question

Hi there, I'm hoping this is a quick question. I've had a look on google but to no avail.
Is it possible to find all images within an indesign document that are below 300dpi. I've got a lot of images placed in a document, quite a lot were low res (not all, but a lot) just for quickness to begin with...but now I need to replace them with the high res for print, and theres LOADS so i don't really wanna do it manually.
I know when you do preflight indesign will tell you if there are any images using RGB colour space, but will it do somehting similar with image quality?
Mac OSX 10.5.8, InDesign CS3

Answer 1

Okay, here is a fast one but it seems to do the job.
Copy the text in the frame below into a plain text document using Notepad, Textedit (in plain text mode!), or -- safest -- InDesign's own ESTK Editor that comes installed with the package. Save as "ReportBadResolution.jsx" in your User Scripts folder (see also InDesignSecret's How to install scripts in InDesign).  Double-click to run.
If nothing happens, all images are okay. If you get an error somewhere, you have used images in a way I did not foresee (and thus didn't script how to handle these); try to report what goes wrong where and on what sort of image, if possible.
If the script does find anything wrong -- it checks for a minimum resolution of 300 dpi and, as a bonus, on badly scaled images -- it will create a new blank document and fill a text frame with the relevant information: image name, page, and x/y resolutions. It creates only one single page so if you get an 'overset text plus' at the bottom you have lots and lots of bad images ...
Here's the script to copy:
//DESCRIPTION:Report Bad Resolutions for a New Year
// No Guarantees, Ltd. Use at your own risk.
// Jongware, 05-Feb-2010
// Minimum dpi allowed:
var minimumValue = 300;
// Alert when x/y scaling is off by this much percents:
var percentageScaling = 1;
var lowResList = new Array;
for (aGraphic=0; aGraphic<app.activeDocument.allGraphics.length; aGraphic++)
oneGraphic = app.activeDocument.allGraphics[aGraphic];
try {
  xres = oneGraphic.effectivePpi[0];
  yres = oneGraphic.effectivePpi[1];
  if (xres < minimumValue || yres < minimumValue)
   lowResList.push (oneGraphic);
  else
   if (xres < yres)
    scaling = 100*yres/xres;
   else
    scaling = 100*xres/yres;
   if (scaling > 100+percentageScaling)
    lowResList.push (oneGraphic);
} catch (_) {}
if (lowResList.length > 0)
doc = app.documents.add();
frame = doc.textFrames.add({geometricBounds:[0,0,doc.documentPreferences.pageHeight, doc.documentPreferences.pageWidth]});
txt = '';
for (i=0; i<lowResList.length; i++)
  pg = ultimateParent (lowResList[i]);
  txt = txt+"File: "+lowResList[i].itemLink.name;
  if (pg.parent instanceof(MasterSpread))
   txt = txt+' on Master spread '+pg.name;
  else
   if (pg instanceof(Spread))
    txt = txt+' on clipboard of pg '+pg.pages[0].name;
    for (j=1; j<pg.pages.length; j++)
     txt += '-'+pg.pages[j].name;
   } else
    txt = txt+' on pg '+pg.name;
  txt = txt+' has xres: '+lowResList[i].effectivePpi[0]+', yres: '+lowResList[i].effectivePpi[1]+'\n';
frame.contents = txt;
} else
alert ("No images have a resolution less than "+minimumValue+" dpi");
function ultimateParent(obj)
while (1)
  obj = obj.parent;
  if (obj.constructor.name == "Page")
   break;
  if (obj.constructor.name == "Character")
   obj = obj.parentTextFrames[0];
  if (obj.constructor.name == "Spread" || obj.constructor.name == "MasterSpread")
   break;
return obj;