CLAUDE: LoG isolation test (curt.log_ident) - identity vs pure-LoG kernels, aberrations skipped

Andrey's discriminator for the fold-vs-kernel-interaction question: with
rend_test + new 'RT render LoG isolation (identity krnl)' ON, saves
-CUAS-RT-RENDER-ID (identity kernels: q0=1, q1..3=0, CltExtra=0 - aberration
correction AND fractional offsets skipped), -ID-LOG-ORACLE (pixel LoG of -ID),
and -LOG-ONLY (pure-LoG kernels, CuasLogFold.uniformKernels(log_td)).
If -LOG-ONLY vs -ID-LOG-ORACLE residual persists, the fold/L0 is wrong; if it
collapses to the wrap floor, the aberration-kernel interaction is responsible.
Refactor: pixel-LoG application extracted to applyPixelLog(); log_test and
log_ident share the kernel fetch/restore (finally).

Evidence so far (offline, this evening's run): per-sensor high-bin tilt varies
s07 +1.3% .. s01 +2.4% with identical scene content => kernel-dependent;
per-quadrant deviation maps identical (no single-coefficient signature);
kx=0 column regionally incoherent (row-structure channel, separate issue).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/main/java/com/elphel/imagej/cuas/rt/CuasLogFold.java

@@ -118,6 +118,52 @@ public class CuasLogFold {
 		return folded;
 	}
 
+	/**
+	 * Build space-INVARIANT kernels in the shape of a template kernel array:
+	 * quadrant 0 = the given per-bin response (null = all-ones = IDENTITY, i.e.
+	 * aberration correction skipped), quadrants 1..3 = 0, CltExtra = all zeros
+	 * (no fractional offsets). For the LoG-only / identity isolation test
+	 * (Andrey 07/06/2026: separate the fold mechanism from the aberration
+	 * kernel content). By Claude on 07/06/2026.
+	 * @param template  existing kernels supplying the array shape
+	 * @param response  per-bin quadrant-0 response [64], or null for identity
+	 * @return new kernel array, same shape as template
+	 */
+	public static double [][][][][][] uniformKernels(
+			double [][][][][][] template,
+			double []           response) {
+		double [][][][][][] uni = new double [template.length][][][][][];
+		for (int ncam = 0; ncam < template.length; ncam++) {
+			if (template[ncam] == null) continue;
+			uni[ncam] = new double [template[ncam].length][][][][];
+			for (int col = 0; col < template[ncam].length; col++) {
+				if (template[ncam][col] == null) continue;
+				uni[ncam][col] = new double [template[ncam][col].length][][][];
+				for (int ty = 0; ty < template[ncam][col].length; ty++) {
+					if (template[ncam][col][ty] == null) continue;
+					uni[ncam][col][ty] = new double [template[ncam][col][ty].length][][];
+					for (int tx = 0; tx < template[ncam][col][ty].length; tx++) {
+						double [][] ktile = template[ncam][col][ty][tx];
+						if (ktile == null) continue;
+						double [][] utile = new double [ktile.length][];
+						for (int p = 0; p < ktile.length; p++) {
+							utile[p] = new double [ktile[p].length]; // zeros
+							if (p == 0) {
+								if (response != null) {
+									System.arraycopy(response, 0, utile[0], 0, response.length);
+								} else {
+									java.util.Arrays.fill(utile[0], 1.0); // identity
+								}
+							}
+						}
+						uni[ncam][col][ty][tx] = utile;
+					}
+				}
+			}
+		}
+		return uni;
+	}
+
 	/** Inherent per-tap attenuation of a TD per-bin multiply: pixel-domain
 	 *  equivalent kernel taps are scaled by cos(pi*dx/(2*TS))*cos(pi*dy/(2*TS))
 	 *  (the lapped-window/convolution non-commutation term; same weights as

src/main/java/com/elphel/imagej/cuas/rt/CuasRender.java

@@ -295,16 +295,29 @@ public class CuasRender {
 				mb_en, mb_tau, mb_max_gain, ts_names, debugLevel);
 		saveRenderHyper(center_CLT, "-CUAS-RT-RENDER", rendered, ts_names,
 				img_width, img_height, num_comps);
-		// ---- LoG A/B (curt.log_test): the aberration+LoG kernel-fold validation
-		// (roadmap RT-seed step 1b). Two more comparable hyperstacks:
-		//   -LOG-ORACLE: the EXISTING pre-DNN pixel-domain LoG (convolve2DLReLU,
-		//                LINEAR alpha=1) applied to the product above;
-		//   -LOG-FOLDED: same render chain, but the LoG folded into the aberration
-		//                kernels (CuasLogFold) and re-uploaded to the GPU - NO
-		//                pixel-domain convolution. Original kernels restored after.
-		// Offline compare (attic/CLAUDE/compare_cuda_versions.py --only LOG-) is
-		// the match verdict. By Claude on 07/06/2026, Andrey's step-1b spec.
-		if (clt_parameters.curt.log_test) {
+		// ---- LoG A/B (curt.log_test / curt.log_ident): the aberration+LoG
+		// kernel-fold validation (roadmap RT-seed step 1b). Comparable hyperstacks:
+		//   log_test:  -LOG-ORACLE (product above x the EXISTING pre-DNN pixel LoG,
+		//              convolve2DLReLU LINEAR alpha=1) + -LOG-FOLDED (same render,
+		//              LoG folded into the aberration kernels - no pixel conv).
+		//   log_ident: -ID (IDENTITY kernels - aberrations skipped) + -ID-LOG-ORACLE
+		//              (pixel LoG of -ID) + -LOG-ONLY (pure-LoG kernels). Isolates
+		//              the fold mechanism from the aberration-kernel content
+		//              (Andrey 07/06/2026: if -LOG-ONLY vs -ID-LOG-ORACLE residual
+		//              persists, the fold/L0 is wrong; if it collapses to the wrap
+		//              floor, the aberration-kernel interaction was responsible).
+		// Original kernels ALWAYS restored. Offline verdict:
+		// attic/CLAUDE/compare_cuda_versions.py --only LOG-,ID. By Claude on 07/06/2026.
+		if (clt_parameters.curt.log_test || clt_parameters.curt.log_ident) {
+			final GpuQuad gpuQuad = center_CLT.getGPUQuad();
+			final double [][][][][][] orig_kernels = gpuQuad.getQuadCLT().getCLTKernels();
+			if (orig_kernels == null) {
+				System.out.println("testRenderSequence(): LoG A/B ERROR - getCLTKernels()==null (kernels never loaded?), skipping LoG tests");
+				return;
+			}
+			final double [] log_td = CuasLogFold.getLogTd(
+					clt_parameters.curt.psf_radius,
+					clt_parameters.curt.n_sigma);
 			// EXACT pre-DNN LoG: same class, same construction as CuasDetectRT.detectTargets
 			final CuasRTUtils cuasRTUtils = new CuasRTUtils (
 					clt_parameters.curt.psf_radius,     // double   psf_radius,
@@ -316,40 +329,15 @@ public class CuasRender {
 					clt_parameters.curt.vel_suppr_rad,  // int      vel_suppr_rad,
 					img_width,                          // int      width,
 					img_height);                        // int      height
-			final double [] kernel2d = cuasRTUtils.getKernel2d();
-			System.out.println("testRenderSequence(): LoG A/B - applying pixel-domain LoG (LINEAR) for -LOG-ORACLE");
-			for (int ns = 0; ns < rendered.size(); ns++) { // in place: slices replaced, originals already saved
-				final float [][] r = rendered.get(ns);
-				if (r == null) continue;
-				for (int nc = 0; nc < r.length; nc++) {
-					if (r[nc] == null) continue;
-					final double [] dslice = new double [r[nc].length];
-					for (int i = 0; i < dslice.length; i++) dslice[i] = r[nc][i];
-					final double [] dlog = cuasRTUtils.convolve2DLReLU(
-							dslice,    // final double [] data,
-							kernel2d,  // final double [] kernel, // square
-							null,      // double []       result_in,
-							1.0);      // final double    alpha) - LINEAR (the standing ruling)
-					final float [] fslice = new float [dlog.length];
-					for (int i = 0; i < fslice.length; i++) fslice[i] = (float) dlog[i];
-					r[nc] = fslice;
-				}
-			}
-			saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-LOG-ORACLE", rendered, ts_names,
-					img_width, img_height, num_comps);
-			rendered.clear(); // release ~11GB before the second render pass
-			// ---- second pass: folded aberration+LoG kernels on the GPU ----
-			final GpuQuad gpuQuad = center_CLT.getGPUQuad();
-			final double [][][][][][] orig_kernels = gpuQuad.getQuadCLT().getCLTKernels();
-			if (orig_kernels == null) {
-				System.out.println("testRenderSequence(): LoG A/B ERROR - getCLTKernels()==null (kernels never loaded?), skipping -LOG-FOLDED");
-			} else {
-				final double [] log_td = CuasLogFold.getLogTd(
-						clt_parameters.curt.psf_radius,
-						clt_parameters.curt.n_sigma);
-				System.out.println("testRenderSequence(): LoG A/B - uploading FOLDED aberration+LoG kernels (CuasLogFold, tap-precompensated)");
-				gpuQuad.setConvolutionKernels(CuasLogFold.foldKernels(orig_kernels, log_td), true);
-				try {
+			try {
+				if (clt_parameters.curt.log_test) {
+					System.out.println("testRenderSequence(): LoG A/B - applying pixel-domain LoG (LINEAR) for -LOG-ORACLE");
+					applyPixelLog(rendered, cuasRTUtils); // in place: originals already saved
+					saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-LOG-ORACLE", rendered, ts_names,
+							img_width, img_height, num_comps);
+					rendered.clear(); // release ~11GB before the next render pass
+					System.out.println("testRenderSequence(): LoG A/B - uploading FOLDED aberration+LoG kernels (CuasLogFold, tap-precompensated)");
+					gpuQuad.setConvolutionKernels(CuasLogFold.foldKernels(orig_kernels, log_td), true);
 					final ArrayList<String> ts_names2 = new ArrayList<String>();
 					final ArrayList<float [][]> rendered2 = renderPass(
 							clt_parameters, center_CLT, quadCLTs, image_dtt, ers_center,
@@ -357,13 +345,63 @@ public class CuasRender {
 							mb_en, mb_tau, mb_max_gain, ts_names2, debugLevel);
 					saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-LOG-FOLDED", rendered2, ts_names2,
 							img_width, img_height, num_comps);
-				} finally { // ALWAYS restore the original kernels for anything running after
-					gpuQuad.setConvolutionKernels(orig_kernels, true);
-					System.out.println("testRenderSequence(): LoG A/B - original kernels restored");
 				}
+				if (clt_parameters.curt.log_ident) {
+					System.out.println("testRenderSequence(): LoG A/B - uploading IDENTITY kernels (aberrations skipped)");
+					gpuQuad.setConvolutionKernels(CuasLogFold.uniformKernels(orig_kernels, null), true);
+					final ArrayList<String> ts_id = new ArrayList<String>();
+					final ArrayList<float [][]> rend_id = renderPass(
+							clt_parameters, center_CLT, quadCLTs, image_dtt, ers_center,
+							center_disparity, pXpYD_center, cond_cfg, margin,
+							mb_en, mb_tau, mb_max_gain, ts_id, debugLevel);
+					saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-ID", rend_id, ts_id,
+							img_width, img_height, num_comps);
+					System.out.println("testRenderSequence(): LoG A/B - applying pixel-domain LoG (LINEAR) for -ID-LOG-ORACLE");
+					applyPixelLog(rend_id, cuasRTUtils);
+					saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-ID-LOG-ORACLE", rend_id, ts_id,
+							img_width, img_height, num_comps);
+					rend_id.clear();
+					System.out.println("testRenderSequence(): LoG A/B - uploading PURE-LoG kernels (LoG-only, aberrations skipped)");
+					gpuQuad.setConvolutionKernels(CuasLogFold.uniformKernels(orig_kernels, log_td), true);
+					final ArrayList<String> ts_lo = new ArrayList<String>();
+					final ArrayList<float [][]> rend_lo = renderPass(
+							clt_parameters, center_CLT, quadCLTs, image_dtt, ers_center,
+							center_disparity, pXpYD_center, cond_cfg, margin,
+							mb_en, mb_tau, mb_max_gain, ts_lo, debugLevel);
+					saveRenderHyper(center_CLT, "-CUAS-RT-RENDER-LOG-ONLY", rend_lo, ts_lo,
+							img_width, img_height, num_comps);
+				}
+			} finally { // ALWAYS restore the original kernels for anything running after
+				gpuQuad.setConvolutionKernels(orig_kernels, true);
+				System.out.println("testRenderSequence(): LoG A/B - original kernels restored");
+			}
+			System.out.println("testRenderSequence(): LoG A/B done - compare the LOG products offline"+
+					" (attic/CLAUDE/compare_cuda_versions.py)");
+		}
+	}
+
+	/** Convolve every slice with the EXISTING pre-DNN pixel-domain LoG (LINEAR
+	 *  alpha=1, NaN-aware), replacing slices in place. By Claude on 07/06/2026. */
+	private static void applyPixelLog(
+			final ArrayList<float [][]> rendered,
+			final CuasRTUtils           cuasRTUtils) {
+		final double [] kernel2d = cuasRTUtils.getKernel2d();
+		for (int ns = 0; ns < rendered.size(); ns++) {
+			final float [][] r = rendered.get(ns);
+			if (r == null) continue;
+			for (int nc = 0; nc < r.length; nc++) {
+				if (r[nc] == null) continue;
+				final double [] dslice = new double [r[nc].length];
+				for (int i = 0; i < dslice.length; i++) dslice[i] = r[nc][i];
+				final double [] dlog = cuasRTUtils.convolve2DLReLU(
+						dslice,    // final double [] data,
+						kernel2d,  // final double [] kernel, // square
+						null,      // double []       result_in,
+						1.0);      // final double    alpha) - LINEAR (the standing ruling)
+				final float [] fslice = new float [dlog.length];
+				for (int i = 0; i < fslice.length; i++) fslice[i] = (float) dlog[i];
+				r[nc] = fslice;
 			}
-			System.out.println("testRenderSequence(): LoG A/B done - compare -LOG-ORACLE vs -LOG-FOLDED offline"+
-					" (attic/CLAUDE/compare_cuda_versions.py --only LOG-)");
 		}
 	}
 

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

@@ -29,6 +29,7 @@ public class CuasRtParameters {
 	public boolean  pose_stored =     false; // DEBUG: decouple rendering/measurement from the LMA - use the STORED (oracle vintage) pose for every scene, no adjustment; one leanMeasure per scene feeds -POSE-RT-HYPER/-CORR2D/-COMPOSITE. The composite must then match the oracle CUAS-MERGED-CUAS-DBG renders tile-for-tile. Lean engine only. // By Claude on 07/04/2026
 	public boolean  rend_test =       false; // RT full-render product (CuasRender.testRenderSequence): per scene raw /jp4/ -> conditionSceneToGpu -> virtual-grid render at BORROWED stored pose+ERS rates -> -CUAS-RT-RENDER hyperstack [s00..s15, merged][scenes], comparable to -CUAS-INDIVIDUAL/MERGED-CUAS-DBG. NON-exclusive: runs AFTER the pose stage when both are ON (the pose stage is part of the RT cycle - Andrey 07/06/2026). // By Claude on 07/05/2026
 	public boolean  log_test =        false; // LoG A/B with the RT render (CuasRender): also save -CUAS-RT-RENDER-LOG-ORACLE (product convolved with the EXISTING pre-DNN pixel LoG, LINEAR alpha=1) and -CUAS-RT-RENDER-LOG-FOLDED (same render, LoG folded into the GPU aberration kernels via CuasLogFold - no pixel convolution; originals restored). The aberration+LoG kernel-fold validation (RT-seed step 1b). // By Claude on 07/06/2026
+	public boolean  log_ident =       false; // LoG ISOLATION test with the RT render (CuasRender): render with IDENTITY kernels (-CUAS-RT-RENDER-ID, aberrations skipped), pixel-LoG it (-ID-LOG-ORACLE), and render with PURE-LoG kernels (-LOG-ONLY). If -LOG-ONLY vs -ID-LOG-ORACLE residual persists, the fold/L0 is wrong; if it collapses to the wrap floor, the aberration-kernel interaction was responsible (Andrey 07/06/2026). // By Claude on 07/06/2026
 	public boolean  dbg_fpixels =     true;  // save the ORACLE debug renders during ingest (prepareFpixels): -CUAS-INDIVIDUAL-CUAS-DBG (an EXTRA per-sensor render pass, ~11GB) + -CUAS-MERGED-CUAS-DBG (save only - the merged render is the production input regardless). Was hardcoded. Turn OFF to save the render time and disk once the RT chain (-CUAS-RT-RENDER) is the trusted full render. // By Claude on 07/05/2026
 	public double   fz_inter =        10000.0; // RT fat zero, INTER (pose/motion: scene x virtual-center correlation). DECOUPLED from the legacy gpu_fatz*/AUX switches (which stay untouched for non-RT/FOPEN). Value is for a single physical-pair amplitude; FZ ~ amplitude^2 in the GPU normalize - scale down x4..x16 for consolidated-average applications as needed. 10000 = the proven oracle INTER operating point (the lean code erroneously used the INTRA value before). // By Claude on 07/05/2026
 	public double   fz_intra =        2000.0; // RT fat zero, INTRA (ranging/disparity: sensor-pair correlations within one scene). Reserved for the RT ranging path; same decoupling/scaling notes as fz_inter. // By Claude on 07/05/2026
@@ -116,6 +117,8 @@ public class CuasRtParameters {
 				"Full RT-chain render: raw jp4 -> conditioning -> virtual-grid render at borrowed stored poses/ERS; saves -CUAS-RT-RENDER [s00..s15+merged][scenes], comparable to the -CUAS-*-DBG oracle products. NON-exclusive: runs AFTER the pose stage when both are ON.");
 		gd.addCheckbox ("RT render LoG A/B (folded kernels)",        this.log_test, // By Claude on 07/06/2026
 				"With the RT render ON: also save -CUAS-RT-RENDER-LOG-ORACLE (the product convolved with the EXISTING pre-DNN pixel-domain LoG, LINEAR) and -CUAS-RT-RENDER-LOG-FOLDED (same render with the LoG FOLDED into the GPU aberration kernels - no pixel convolution; original kernels restored after). Compare offline: the aberration+LoG kernel-fold validation (roadmap RT-seed step 1b).");
+		gd.addCheckbox ("RT render LoG isolation (identity krnl)",   this.log_ident, // By Claude on 07/06/2026
+				"With the RT render ON: render with IDENTITY kernels (-ID, aberrations skipped), apply the pixel LoG (-ID-LOG-ORACLE), then render with PURE-LoG kernels (-LOG-ONLY). Isolates the LoG fold mechanism from the aberration-kernel content: persistent -LOG-ONLY vs -ID-LOG-ORACLE residual = the fold is wrong; collapse to the wrap floor = kernel interaction. Two extra render passes.");
 		gd.addCheckbox ("Save oracle DBG renders (11GB)",            this.dbg_fpixels, // By Claude on 07/05/2026
 				"Save -CUAS-INDIVIDUAL-CUAS-DBG (an EXTRA per-sensor render pass, ~11GB) and -CUAS-MERGED-CUAS-DBG during ingest. Turn OFF to save render time and disk once -CUAS-RT-RENDER (RT render test) is the trusted full render.");
 		gd.addNumericField("RT fat zero INTER (pose/motion)",        this.fz_inter, 1,9,"", // By Claude on 07/05/2026
@@ -260,6 +263,7 @@ public class CuasRtParameters {
 		this.pose_stored =         gd.getNextBoolean();      // By Claude on 07/04/2026
 		this.rend_test =           gd.getNextBoolean();      // By Claude on 07/05/2026
 		this.log_test =            gd.getNextBoolean();      // By Claude on 07/06/2026
+		this.log_ident =           gd.getNextBoolean();      // By Claude on 07/06/2026
 		this.dbg_fpixels =         gd.getNextBoolean();      // By Claude on 07/05/2026
 		this.fz_inter =            gd.getNextNumber();       // By Claude on 07/05/2026
 		this.fz_intra =            gd.getNextNumber();       // By Claude on 07/05/2026
@@ -344,6 +348,7 @@ public class CuasRtParameters {
 		properties.setProperty(prefix+"pose_stored",     this.pose_stored+"");    // boolean // By Claude on 07/04/2026
 		properties.setProperty(prefix+"rend_test",       this.rend_test+"");      // boolean // By Claude on 07/05/2026
 		properties.setProperty(prefix+"log_test",        this.log_test+"");       // boolean // By Claude on 07/06/2026
+		properties.setProperty(prefix+"log_ident",       this.log_ident+"");      // boolean // By Claude on 07/06/2026
 		properties.setProperty(prefix+"dbg_fpixels",     this.dbg_fpixels+"");    // boolean // By Claude on 07/05/2026
 		properties.setProperty(prefix+"fz_inter",        this.fz_inter+"");       // double  // By Claude on 07/05/2026
 		properties.setProperty(prefix+"fz_intra",        this.fz_intra+"");       // double  // By Claude on 07/05/2026
@@ -428,6 +433,7 @@ public class CuasRtParameters {
 		if (properties.getProperty(prefix+"pose_stored")!=null)     this.pose_stored=Boolean.parseBoolean(properties.getProperty(prefix+"pose_stored"));       // By Claude on 07/04/2026
 		if (properties.getProperty(prefix+"rend_test")!=null)       this.rend_test=Boolean.parseBoolean(properties.getProperty(prefix+"rend_test"));           // By Claude on 07/05/2026
 		if (properties.getProperty(prefix+"log_test")!=null)        this.log_test=Boolean.parseBoolean(properties.getProperty(prefix+"log_test"));             // By Claude on 07/06/2026
+		if (properties.getProperty(prefix+"log_ident")!=null)       this.log_ident=Boolean.parseBoolean(properties.getProperty(prefix+"log_ident"));           // By Claude on 07/06/2026
 		if (properties.getProperty(prefix+"dbg_fpixels")!=null)     this.dbg_fpixels=Boolean.parseBoolean(properties.getProperty(prefix+"dbg_fpixels"));       // By Claude on 07/05/2026
 		if (properties.getProperty(prefix+"fz_inter")!=null)        this.fz_inter=Double.parseDouble(properties.getProperty(prefix+"fz_inter"));               // By Claude on 07/05/2026
 		if (properties.getProperty(prefix+"fz_intra")!=null)        this.fz_intra=Double.parseDouble(properties.getProperty(prefix+"fz_intra"));               // By Claude on 07/05/2026
@@ -515,6 +521,7 @@ public class CuasRtParameters {
 		cp.pose_stored = this.pose_stored; // By Claude on 07/04/2026
 		cp.rend_test = this.rend_test; // By Claude on 07/05/2026
 		cp.log_test = this.log_test; // By Claude on 07/06/2026
+		cp.log_ident = this.log_ident; // By Claude on 07/06/2026
 		cp.dbg_fpixels = this.dbg_fpixels; // By Claude on 07/05/2026
 		cp.fz_inter = this.fz_inter; // By Claude on 07/05/2026
 		cp.fz_intra = this.fz_intra; // By Claude on 07/05/2026