Fixed no-tile (empty) meshes export

src/main/java/com/elphel/imagej/correction/CorrectionColorProc.java

@@ -266,9 +266,13 @@ public class CorrectionColorProc {
     		}
     		this.denoiseMaskChroma=dmask; // (global, used to return denoise mask to save/show
     		this.denoiseMaskChromaWidth=width; // width of the this.denoiseMaskChroma image
+    	} else {
+    		if ((width <= 0) || (height <= 0)) {
+    			System.out.println("***** BUG oin processColorsWeights: width="+width+", height="+height+" ****");
     		} else {
 	    		gb.blurDouble(dpixels_pr, width, height, colorProcParameters.chromaBrightSigma, colorProcParameters.chromaBrightSigma, 0.01);
 	    		gb.blurDouble(dpixels_pb, width, height, colorProcParameters.chromaBrightSigma, colorProcParameters.chromaBrightSigma, 0.01);
+    		}
     		this.denoiseMaskChroma=null; // (global, used to return denoise mask to save/show
     	}
     	for (i=0;i<dpixels_pr.length;i++) {

src/main/java/com/elphel/imagej/tileprocessor/CLTPass3d.java

@@ -169,8 +169,12 @@ public class CLTPass3d{
 					selected[ty * tilesX + tx] = false; // may be omitted
 				}
 			}
+			if (maxX < 0) {
+				texture_bounds = null;
+			} else {
 				texture_bounds = new Rectangle(minX, minY, maxX - minX +1, maxY - minY +1 );
 			}
+		}
 
 		public  Rectangle  getTextureBounds(){
 			return texture_bounds;

src/main/java/com/elphel/imagej/tileprocessor/QuadCLT.java

@@ -8226,6 +8226,7 @@ public class QuadCLT {
 						  threadsMax,  // maximal number of threads to launch
 						  updateStatus,
 						  batch_mode ? -5: debugLevel);
+				  if (texturePath != null) { // null if empty image
 					  double [] scan_disparity = new double [tilesX * tilesY];
 					  int indx = 0;
 					  //		  boolean [] scan_selected = scan.getSelected();
@@ -8263,6 +8264,7 @@ public class QuadCLT {
 					  bgndScan.setSelected(bg_sel_backup);
 				  }
 			  }
+		  }
 
 
 
@@ -8300,7 +8302,9 @@ public class QuadCLT {
 					  threadsMax,  // maximal number of threads to launch
 					  updateStatus,
 					  batch_mode ? -5: debugLevel);
-
+			  if (texturePath == null) {
+				  continue; // empty image
+			  }
 			  CLTPass3d scan = tp.clt_3d_passes.get(scanIndex);
 
 			  // TODO: use new updated disparity, for now just what was forced for the picture
@@ -8388,6 +8392,9 @@ public class QuadCLT {
 			  double          maxDispTriangle
 			  ) throws IOException
 	  {
+		  if (bounds == null) {
+			  return;
+		  }
 		  int [][] indices =  tp.getCoordIndices( // starting with 0, -1 - not selected
 				  bounds,
 				  selected);
@@ -8683,6 +8690,10 @@ public class QuadCLT {
 		  boolean [] borderTiles = scan.border_tiles;
 		  double [][][][] texture_tiles = scan.texture_tiles;
 		  scan.updateSelection(); // update .selected field (all selected, including border) and Rectangle bounds
+		  if (scan.getTextureBounds() == null) {
+			  System.out.println("getPassImage(): Empty image!");
+			  return null;
+		  }
 		  double [][]alphaFade = tp.getAlphaFade(clt_parameters.transform_size);
 		  if ((debugLevel > 0) && (scanIndex == 1)) {
 			  String [] titles = new String[16];
@@ -8754,6 +8765,9 @@ public class QuadCLT {
 
 		  int width = resize ? (clt_parameters.transform_size * scan.getTextureBounds().width): (clt_parameters.transform_size * tilesX);
 		  int height = resize ? (clt_parameters.transform_size * scan.getTextureBounds().height): (clt_parameters.transform_size * tilesY);
+		  if ((width <= 0) || (height <= 0)) {
+			  System.out.println("***** BUG in getPassImage(): width="+width+", height="+height+", resize="+resize+" ****");
+		  }
 
 		  ImagePlus imp_texture_cluster = linearStackToColor(
 				  clt_parameters,