Image Layers
The Image Layers dropdown in the Chloros Image Viewer allows you to quickly switch between different versions of the same image - from the original captures to processed reflectance outputs and calculated index images.
What are Image Layers?
In Chloros, layers refer to the different image outputs available for a single source image. When you process images, Chloros creates multiple versions:
Original images (JPG and RAW files from your camera)
Reflectance calibrated outputs (if reflectance calibration was enabled)
Target images (if the image contains calibration targets)
Index images (NDVI, NDRE, GNDVI, etc. if indices were configured)
The Layer Selector dropdown in the top-right of the Image Viewer lets you instantly switch between these versions without leaving the viewer.
Available Layer Types
JPG
The original JPG preview image from your camera
Always available for all images
Unprocessed, as captured by the camera
Fastest to load and display
When to view:
Quick preview of original capture
Checking image composition and framing
Verifying capture quality before processing
RAW (Original)
The original RAW sensor data from your camera
Debayered with no post processing applied
Higher bit depth than JPG (typically 12-bit or 14-bit sensor data)
When to view:
Inspecting original sensor data quality
Checking for sensor issues or artifacts
Comparing before/after processing results
RAW (Target)
Only appears for images identified as containing calibration targets
Shows the original RAW image with target detected
Used to verify target detection was successful
When to view:
Confirming calibration targets were detected correctly
Checking target image quality
Troubleshooting calibration issues
RAW (Reflectance)
The calibrated reflectance output image
Vignette corrected (if enabled in processing)
Reflectance calibrated using target data (if enabled)
Multi-band TIFF with all camera channels
Pixel values represent percent reflectance (when using percent mode)
Ready to manipulate with the Index/LUT Sandbox
When to view:
Inspecting calibrated results
Verifying calibration quality
Checking pixel values for scientific accuracy
Comparing with original to see calibration effects
Recommended: Use RAW (Reflectance) layer when checking pixel values for scientific measurements and analysis.
RAW (NDVI Index)... and similar
Calculated vegetation index image (NDVI in this example)
The index name changes based on which index was configured during processing
Examples: RAW (NDVI Index), RAW (NDRE Index), RAW (GNDVI Index), etc.
Single-band grayscale image showing index calculation results
One layer appears for each index configured in Project Settings
Possible index names:
RAW (NDVI Index)
RAW (NDRE Index)
RAW (GNDVI Index)
RAW (OSAVI Index)
RAW (EVI Index)
RAW (SAVI Index)
And many more... (see Multispectral Index Formulas)
When to view:
Examining index calculation results
Checking index value ranges
Identifying areas of interest
Verifying index images before using in GIS or analysis
Using the Layer Selector
Opening the Dropdown
Open an image in fullscreen mode (click any thumbnail in the Image Viewer)
Locate the layer dropdown in the top-right corner of the viewer
The dropdown shows the currently selected layer (e.g., "JPG")
Click the dropdown to see all available layers
Switching Layers
Click the layer dropdown to open the list
All available layers for the current image are shown
Click any layer name to switch to that version
The image updates immediately to show the selected layer
Quick switching:
The dropdown remembers your last selection
When navigating to the next image, Chloros attempts to show the same layer type
If that layer doesn't exist on the next image, it defaults to JPG
Layer Availability
Not all layers are available for every image:
Always available:
✅ JPG (every image has a JPG preview)
Conditionally available:
⚠️ RAW (Original) - Only if image was captured in RAW or RAW+JPG mode
⚠️ RAW (Target) - Only if image contains detected calibration targets
⚠️ RAW (Reflectance) - Only after processing with reflectance calibration enabled
⚠️ RAW ([Index] Index) - Only after processing with indices configured
Layer Persistence
Navigating Between Images
When you navigate to a different image (using arrow keys or clicking thumbnails):
Layer preference is preserved:
If viewing "RAW (Reflectance)", next image shows "RAW (Reflectance)" (if available)
If viewing "RAW (NDVI Index)", next image shows "RAW (NDVI Index)" (if available)
If the same layer doesn't exist, defaults to JPG
Example workflow:
Open Image 1, switch to RAW (NDVI Index)
Press → to view Image 2
Image 2 automatically displays RAW (NDVI Index) layer
Continue navigating - all images show NDVI layer
Very efficient for reviewing index results across many images
Common Workflows
Workflow 1: Before/After Comparison
Goal: Compare original vs. calibrated image
Open processed image in Image Viewer
Select RAW (Original) from dropdown
Note the vignetting and uncalibrated values
Switch to RAW (Reflectance) from dropdown
Compare - vignetting removed, values calibrated
Workflow 2: Index Review
Goal: Quickly review NDVI results across dataset
Open first processed image
Select RAW (NDVI Index) from dropdown
Use → arrow key to navigate to next image
NDVI layer persists automatically
Continue through all images, checking NDVI patterns
Switch to RAW (NDRE Index) to compare
Workflow 3: Target Verification
Goal: Verify all target images were detected correctly
Navigate to a target image
Select RAW (Target) from dropdown
Verify calibration targets are clearly visible and detected
Navigate to next target image
Repeat verification for all targets
Workflow 4: Pixel Value Inspection
Goal: Check reflectance values for scientific accuracy
Open processed image
Select RAW (Reflectance) layer
Enable Pixel Percent mode (button in top-right toolbar)
Move cursor over vegetation areas
Verify pixel values are in expected ranges (30-70% for NIR, 5-15% for Red)
Check soil and water areas for appropriate values
Understanding Pixel Values by Layer
Different layers show different pixel value ranges:
JPG Layer
Range: 0-255 (8-bit)
Meaning: Display values, gamma-corrected
Use: Visual inspection only, not for scientific measurement
RAW (Original)
Range: 0-65535 (16-bit)
Meaning: Raw sensor digital numbers
Use: Checking sensor performance, not calibrated
RAW (Reflectance)
Range: 0-65,535 (16-bit TIFF) or 0.0-1.0 (32-bit Percent)
Meaning: Calibrated percent reflectance
Use: Scientific measurements and analysis
For 16-bit TIFF: Divide by 65,535 to get percent reflectance For 32-bit Percent: Values directly represent percent (0.5 = 50% reflectance)
RAW (Index Images)
Range: Varies by index (typically -1.0 to +1.0 for normalized indices)
Meaning: Index calculation result
Examples:
NDVI: -1 to +1 (vegetation typically 0.4 to 0.9)
NDRE: -1 to +1 (stress detection)
EVI: 0 to 1 (enhanced vegetation)
Tips and Best Practices
Efficient Layer Switching
Keyboard shortcut awareness: While there's no keyboard shortcut for layers, navigation arrows (←/→) work across all layers
Consistent workflows: Pick one layer (e.g., NDVI) and review entire dataset before switching to another
Quick comparisons: Toggle between Original and Reflectance to verify processing quality
Performance Considerations
JPG loads fastest: Use for quick navigation through many images
RAW layers load slower: Higher resolution and bit depth
Index layers: Similar speed to Reflectance layers
First load is slowest: Subsequent views of same layer are cached and faster
Quality Verification
Always check RAW (Original): Verify source data quality before trusting processed outputs
Compare layers: Use layer switching to validate processing worked correctly
Check index ranges: Use Pixel Percent mode with index layers to verify values are reasonable
Troubleshooting
Layer Not Available
Problem: Expected layer doesn't appear in dropdown
Possible causes:
Image wasn't processed (only JPG and RAW (Original) available)
Reflectance calibration was disabled during processing
Specific index wasn't configured in Project Settings
Image is a target-only image (no indices generated for targets)
Solutions:
Verify image was processed (check output folder for processed files)
Check Project Settings to confirm indices were configured
Reprocess with desired indices enabled
Wrong Layer Shown
Problem: Image opens in unexpected layer
Cause: Layer preference from previous image carried forward, but that layer doesn't exist on current image
Solution: Chloros automatically falls back to JPG when preferred layer unavailable - this is normal behavior
Can't See Calibration Targets
Problem: RAW (Target) layer doesn't show target detection
Possible causes:
Targets weren't detected during processing
Image doesn't actually contain targets
Target detection settings too strict
Solutions:
Check Debug Log for "Target found" messages
Verify image actually contains visible calibration targets
Adjust target detection settings in Project Settings
Related Features
Image Viewer Tools
When viewing any layer, you can use:
Zoom controls: Magnify to inspect details
Pan: Click and drag to move around zoomed image
Pixel value inspection: See values at cursor location
Navigation arrows: Move between images while maintaining layer
Pixel Percent mode: Toggle between DN and percent display
See Opening an Image Full Screen for complete Image Viewer documentation.
Index/LUT Sandbox
For interactive index testing and visualization:
Real-time index calculation: Test different index formulas
LUT color mapping: Apply color gradients to grayscale indices
Export visualizations: Save colored index images
See Index/LUT Sandbox for details.
Next Steps
Now that you understand image layers:
Opening an Image Full Screen - Complete Image Viewer guide
Index/LUT Sandbox - Interactive index visualization
Multispectral Index Formulas - Available indices reference
Finishing the Processing - Understanding processed outputs
Last updated