1. Which type of enhancement improves contrast by stretching the histogram?
(A) Histogram equalization
(B) Low-pass filtering
(C) Edge detection
(D) Band ratioing
2. Which method is commonly used for reducing haze in satellite images?
(A) Atmospheric correction
(B) Histogram matching
(C) Principal component analysis
(D) Edge sharpening
3. Which spatial filter enhances high-frequency details in an image?
(A) Low-pass filter
(B) Median filter
(C) High-pass filter
(D) Averaging filter
4. Which enhancement technique is effective in highlighting urban features in satellite images?
(A) Band ratioing
(B) NDVI
(C) PCA
(D) Edge enhancement
5. Which method transforms a satellite image to emphasize vegetation?
(A) NDVI
(B) Tasseled Cap
(C) FCC
(D) Band subtraction
6. What is the main purpose of radiometric correction in satellite images?
(A) Geometric alignment
(B) Cloud masking
(C) Adjusting pixel intensity values
(D) Detecting edges
7. Which technique enhances image details by subtracting a low-pass filtered image from the original?
(A) Histogram equalization
(B) Unsharp masking
(C) Band ratioing
(D) PCA
8. What does NDVI stand for?
(A) Normalized Difference Vegetation Index
(B) Normalized Digital Vegetation Image
(C) National Data Visual Index
(D) Non-Destructive Visual Imaging
9. Which of the following is used to reduce striping noise in satellite images?
(A) Destriping filter
(B) Histogram matching
(C) Spectral sharpening
(D) Band stretching
10. Which method uses the statistical distribution of pixel values for image enhancement?
(A) Edge detection
(B) Histogram equalization
(C) Fourier transform
(D) PCA
11. Which image enhancement technique is best for improving visibility in low-contrast satellite images?
(A) Band subtraction
(B) Contrast stretching
(C) Band fusion
(D) Ratio transformation
12. Which of the following is a spectral enhancement method?
(A) Band ratioing
(B) Histogram equalization
(C) Laplacian filtering
(D) Median filtering
13. What does PCA stand for in satellite image enhancement?
(A) Pixel Correction Algorithm
(B) Principal Component Analysis
(C) Projection Contrast Adjustment
(D) Phase Coefficient Adjustment
14. Which enhancement technique helps distinguish different land cover types by combining RGB bands?
(A) False color composite
(B) Band ratioing
(C) PCA
(D) NDVI
15. Which color combination is commonly used in false color composites for vegetation?
(A) R: NIR, G: Red, B: Green
(B) R: Blue, G: Red, B: NIR
(C) R: Green, G: Red, B: Blue
(D) R: Red, G: Blue, B: NIR
16. Which process corrects geometric distortions in satellite images?
(A) Radiometric calibration
(B) Georeferencing
(C) NDVI
(D) Band fusion
17. Which frequency domain technique is used to enhance edges?
(A) Fourier transform
(B) Inverse FFT
(C) Low-pass filtering
(D) High-frequency boosting
18. What does atmospheric correction primarily address?
(A) Sensor misalignment
(B) Illumination variations
(C) Atmospheric scattering and absorption
(D) Terrain distortion
19. Which of the following methods improves image clarity by enhancing sharp transitions?
(A) Low-pass filtering
(B) Edge enhancement
(C) Band fusion
(D) NDVI
20. Which tool can be used for visual enhancement in QGIS or ArcGIS?
(A) Color balancing
(B) PCA
(C) Band ratio
(D) Masking
21. Which enhancement method helps to identify water bodies more effectively?
(A) NDBI
(B) NDWI
(C) NDVI
(D) PCA
22. In image enhancement, what does linear contrast stretching involve?
(A) Equalizing histogram bins
(B) Mapping input values to full output range
(C) Subtracting means of bands
(D) Filtering low-frequency noise
23. Which of the following helps to enhance textural features in satellite images?
(A) GLCM
(B) Histogram matching
(C) Band fusion
(D) Ratio transformation
24. Which type of enhancement increases interpretability for human viewers?
(A) Visual enhancement
(B) Radiometric calibration
(C) Spectral unmixing
(D) Classification
25. Which method helps to separate overlapping spectral features?
(A) Band subtraction
(B) Principal component analysis
(C) Histogram equalization
(D) Unsharp masking
26. Which of these is an effect of poor contrast in satellite images?
(A) High frequency of edges
(B) Difficulty in distinguishing features
(C) Over-saturation
(D) Blurred motion
27. Which band combination is ideal for detecting vegetation in Landsat images?
(A) Bands 4-3-2
(B) Bands 5-4-3
(C) Bands 3-2-1
(D) Bands 7-5-3
28. Which technique enhances image contrast without affecting the relative radiance values?
(A) Histogram equalization
(B) Linear stretching
(C) Piecewise contrast enhancement
(D) Logarithmic enhancement
29. Which transformation uses mathematical functions to modify pixel values?
(A) Logarithmic enhancement
(B) NDVI
(C) Ratioing
(D) PCA
30. Which process enhances images for better automated classification accuracy?
(A) Spectral sharpening
(B) Radiometric calibration
(C) PCA
(D) NDVI
31. What does FCC stand for in remote sensing?
(A) Full Color Composition
(B) False Color Composite
(C) Frequency Channel Compression
(D) Filtered Color Coding
32. Which type of enhancement is based on human perception?
(A) Radiometric correction
(B) Contrast stretching
(C) Visual enhancement
(D) Geometric correction
33. Which function is used in MATLAB or Python to apply histogram equalization?
(A) histmatch
(B) histeq
(C) graystretch
(D) imenhance
34. Which filter emphasizes edges and suppresses uniform areas?
(A) Laplacian filter
(B) Median filter
(C) Gaussian filter
(D) Low-pass filter
35. What is the purpose of using high-boost filtering?
(A) Remove noise
(B) Blur image
(C) Enhance details by amplifying high-frequency components
(D) Convert image to grayscale
36. Which enhancement approach can lead to over-enhancement artifacts?
(A) Unsharp masking
(B) PCA
(C) NDVI
(D) Logarithmic enhancement
37. Which technique provides better contrast in areas with minimal brightness variation?
(A) Histogram equalization
(B) Adaptive histogram equalization
(C) Band subtraction
(D) Geometric correction
38. Which is a disadvantage of histogram equalization?
(A) Increases noise
(B) Reduces sharpness
(C) Inconsistent brightness
(D) Nonlinear transformation
39. Which index helps in differentiating between built-up areas and vegetation?
(A) NDWI
(B) NDBI
(C) NDVI
(D) SAVI
40. Which type of enhancement is used to highlight man-made features in a scene?
(A) NDBI
(B) NDVI
(C) FCC
(D) Unsharp masking
41. Which of the following is not a radiometric enhancement?
(A) Contrast stretching
(B) Histogram equalization
(C) Band ratioing
(D) Noise removal
42. Which transformation increases the visibility of subtle image patterns?
(A) Logarithmic
(B) Linear
(C) Constant
(D) Square root
43. Which is a key application of satellite image enhancement?
(A) Data compression
(B) Feature extraction
(C) Bit plane slicing
(D) Keypoint matching
44. Which technique enhances image based on local statistics of pixel neighborhoods?
(A) Adaptive histogram equalization
(B) Global histogram stretching
(C) Band ratioing
(D) PCA
45. Which of the following is a geometric correction process?
(A) Cloud masking
(B) Orthorectification
(C) NDVI calculation
(D) Histogram adjustment
46. Which filter type preserves edges while reducing noise?
(A) Median filter
(B) Average filter
(C) High-pass filter
(D) Laplacian filter
47. Which frequency components are enhanced to sharpen an image?
(A) Low-frequency
(B) Mid-frequency
(C) High-frequency
(D) All-frequency
48. What is the role of band fusion in enhancement?
(A) Reduce noise
(B) Improve resolution and information content
(C) Compress images
(D) Match histograms
49. Which technique is best for enhancing shadowed regions?
(A) Logarithmic transformation
(B) NDVI
(C) PCA
(D) Band fusion
50. Which enhancement technique is commonly used to improve the visibility of features in satellite images taken under varying illumination conditions?
(A) Adaptive histogram equalization
(B) Band subtraction
(C) NDVI
(D) Destriping
