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GCR Section Half Image Logger (SHIL) User Guide

GCR Section Half Image Logger (SHIL) User Guide

Section Half Imaging Logger (SHIL).jpg

I. Introduction533px533px

The section half image logger (SHIL) takes digital images of the flat face of split cores using a line scan camera and generates RGB data. All 'Archive' section halves are imaged on the SHIL. Sediment cores are imaged as soon as possible after splitting and scraping to minimize color changes that occur through oxidation and drying. The SHIL can also be used to image the outside of a whole round hard rock section (see section 360° Imaging Hard Rock for details).

 

Theory of Operation

 

The track system is composed of two slaved linear actuators and a linear encoder that provides precise triggering pulses to a gantry-mounted JAI color line scan camera. The line scan interval is 20 lines/mm (50 microns) and the camera height is adjusted so that image pixels will be square. Light is provided by a number of Advanced Illumination high-current focused light emitting diode (LED) line lights adjusted to precise angles relative to the lens axis in order to evenly illuminate an uneven surface. Motion control is performed using Galil software and hardware coupled to the linear actuators.

 

Line Scan Camera

 

Unlike a "normal" distal photo sensor with a square sensor array, similar to a postage stamp, a line scan camera's array consists of a single line of pixels. Whereas a normal camera captures frames, the line scan camera sees only a single line at a time and sends this line image to a capture card on a dedicated computer. Line by line, the computer compiles the final image.
In some applications, the photographic subject may move in front of the camera on a conveyor belt at a specific combination of object speed and shutter speed. In the case of the SHIL, the camera moves across the sample via a motorized gantry. The combination of gantry travel speed and camera shutter speed is critical and is explained in the Camera Configuration Advanced User Guide.
The line scan camera images only one line of pixels rather than an area and therefore what happens outside the line of view is of no consequence. The line scan camera effectively masks everything other than the single line of pixels being imaged. This fact is key to the effectiveness of the line lights in providing even illumination at different distances from the lens.
The camera lens on the imaging track, Nikon 60 mm macro, does not have 1/2 or 1/3 stops, only whole F/stops: 5.6, 6.3, 8, 11, 16, 22, and 32. F/16 is the minimum aperture needed to achieve the required depth of field to image the subject at varying heights.

II. Procedures

 

A. Preparing the Instrument

 

  1. Double-click the MUT icon on the desktop (Figure 1a) and login using ship credentials. For more information on data uploading see the "Uploading Data to LIMS" section below.

  2. Double-click the IMS icon (Figure 1b). IMS initializes the instrument. Once initialized, the logger is ready to measure the first section.

 

Figure 1. (a) MUT Icon. (b) IMS Icon.

At launch, IMS begins an initialization process:

  • Testing instrument communications

  • Reloading configuration values

  • Homing the pusher arm of the motion control system.

After successful initialization, the IMS Control and Instruments' windows appear (Figure 2).

Figure 2. IMS Control window (left) and Instrument' windows (right).

 

 

The IMS Control panel (Figure 3): Provides access to utilities/editors via drop-down menus.

 

 

Figure 3. Control Panel Drop Down menus.

 

START button will allow the user to begin measurements. Section Information window (Figure 4) will pop up.

 

Figure 4. Section Information window. 

B. Camera Setup and Calibration

The laboratory technician calibrates the system when needed by adjusting camera settings and analyzing an imaged Xrite Color Checker Mini standard (MacBeth card). Be sure to use a 2014 or newer version of the Xrite Color checker because the RGB values used for correction uses the values from the newer standard. The RGB values on the standard are calculated from the L*ab values provided by Xrite. As of Dec 6, 2021 we are using RGB values calculated under an illuminant A. The excel spreadsheet of RGB values of the Xrite color checker using varying illuminants and can be found here. The white square has R=240, G=242, B=235 and the black square R=50, G=50, B=50. A 3-D standard that holds the Xrite color checker and a grey silicon mat is in the SHIL calibration drawer, PP-2B (Figure 5).

Figure 5. 3D standard with Xrite color checker standard.

 

The current light system (Figure 6) obtains nearly uniform illumination intensity from the core’s surface (half or whole round) to the bottom of the liner by a combination of high intensity, overlapping large diameter light source, close coupling to the imaged surface and the “line” image plane.  The bottom edge of the led mount should be set between 2 and 4cm from the image surface.  Note, any height change to the lights requires re-calibration. Heat is removed from the LEDs and transferred to the surrounding air via the copper heat pipes and is cooled with mini fans. While the copper rods can get hot they are not a burn hazard.  However they are very delicate and bend at the slightest touch, so use care when working with the camera lens. For more detailed information on the theory behind the calibration please refer to the Understanding the SHIL Calibration for further reading. Maintain temperature of the lights at 30-40 °C during calibration. LED's of temperature is located above the camera. During a section scan the temperature ranges between 30-36 °C. 

Figure 6. SHIL Camera and Lights set up.

Calibration is conducted in the following steps. 

  1. Physically set the camera at the correct height and focus.  See Camera Height and Focusing.

  2. Set the saturation range for each channel of the CCD while maintaining the white balance between these channels for neutral colors (white, greys and black). See Setting Exposures and Setting Gains.

  3. Correct for uneven lighting, dark noise and pixel flatness. See Pixel Black, Shading and Flat Corrections.

  4. Calibrate and create a correction LUT for each RGB channel. See Image Calibration.

The first three steps are done using the JAI Camera Setup Utility, the 4th step is done using Image Correction Utility.  Before opening the utility you must disable Motion Control so that you can move the camera by hand.

Disable Drive:

1. In the IMS control panel select Motion and then Drive Disable from the dropdown menu (Figure 7). You will have to move the camera by hand for the calibration, disabling the motor allows manual movement of the camera on the track.

 

Figure 7. IMS commands to disable the drive.

 

2. Open JAI Camera Setup utility: In the IMS control panel click Instruments > JAI Camera Settings (Figure 8). The lights turn on automatically when the JAI Camera Setup window opens.

Figure 8. Selecting JAI Camera Setup

 

3. Click Lights OFF (Figure 9). Remember we want to keep the temperature below 39°C. Use the LED read out of the light's temperature located above the camera. 

Figure 9. Software commands to turn the Lights on or off.

 

 

Camera Height and Focusing

 

Camera Height

In practice the camera height rarely changes and this step is not necessary to perform for every calibration but it should be checked at the beginning of each expedition.

 

The goal is to set the across image pixel pitch with a focused camera. Warning this can be tedious and requires two people.

1. Turn on the lights. Remember to maintain temperature of the lights at 30-40 °C.

2. Click the START GRAB button.

3. Move the camera so that it is scanning just the centimeter marks on the QP 101 card (Figure 10).  Also, it is important that the QP 101 card is mounted straight so that the scale lines are parallel to the direction of motion.

 

Figure 10. QP 101 card showing centimeter marks for pixel pitch calibration.

 

4. On the screen you will see the cm lines and vertical peaks on the Profile graph (Figure 11).

Figure 11. Example of the QP-101 marks and the profile graph.

 

5. On the Profile graph, drag the purple and yellow cursors to the center of two adjacent peaks near the center of the image.  These peaks are the centimeter lines in the QP card.

6. Use the graph controls and expand (zoom) the graph horizontally (Figure 12).

 

Figure 12. Cursor placement on the QP 101's centimeter marks in Profile graph. 

 

7. In the expanded view, adjust the cursors so that the are centered in the peak's width (not necessarily the max value). You want to achieve a Pixel Delta of 200 pixels/cm (+/-1px) (Figure 13).

 

Figure 13. Cursor pixel values and span. 

 

A word of caution.

Be careful how you tighten the clamps holding the camera to the T-Slot. Make sure to tighten with even pressure on both sides, if you don't the camera can be offset and you will see the image in the Grab window shift.  The camera attachment method is not ideal and should be replace.

After performing this process you need to check the home position.  When at the home position, the camera should be scanning the edge of the tray where the section is placed against (red strip).  If not, you will need to adjust the home switch on the track until it does.  An improperly set home switch will affect the placement of the crop window and potentially the offsets assigned to the RGB values.

 

Setting Exposures

1.  Click the Gains-Black-Shade-Flat tab (Figure 14).

Figure 14. JAI Camera Setup Window showing the Gains-Black-Shade-Flat tab. The Gains-Black-Shade-Flat tab is outlined in red.

 

2. Click the Clear All Gains, Clear Black Gains, Remove Pixel Black Correction, Remove Shading Correction, and Remove Pixel Gain Correction (Figure 15). You will notice all values in the Master and Black gains go to zero.

Figure 15. Remove the corrections and clear gains.

 

3. Check the camera's f/stop which should either f/16 or f/22 (see Figure 16).  Remember that the higher the f-stop the greater the depth of focus.  The down side is that a higher f-stops means less light and low light levels mean longer exposures - which means slow track speeds for scanning - which could impact core flow in the lab.  So on a low recovery expedition you can afford the longer scan time, so go for f/22 otherwise f/16. If you are doing 360-imaging f/22 is a must.  Check with the LO and EPM if you are unsure of the time needed for scanning sections.      

Figure 18. Setting the F Stop on the Camera.
Figure 18. Setting the F Stop on the Camera.

Figure 16. Setting the F Stop on the Camera. Although the figure says f/22 is recommended (recommended by the manufacturer) onboard we found f/16 works best for our scanning needs.

4. Place the 3D Calibration Standard in the track. The color square must be oriented as shown in Figure 17.

Figure 17. Calibration 3D standard with the Xrite color checker mini.

 

Understand Triggers and Exposures

When the camera moves it will receive trigger pulses from the linear encoder.  Each trigger pulse will start an exposure in the cycle.  The encoder will provide 200 pulses for every centimeter of movement; therefore, the speed of the track controls the time between pulse which controls the maximum allowable exposure period.  The individual exposure periods for the RGB channels must be completed in this time or lines will be dropped.

When setting up the JAI camera we are not moving and not receiving trigger pulses.  In this mode we use the line rate trigger (free run) to simulate the encoder trigger period.

 

When you adjust the Line Trigger Interval (yellow slider in above figure) you will notice that the Max Image Scan Speed value changes.  If you scan faster than this, you will drop lines but you can scan slower without affecting the calibration. 

You can adjust scan speed in the Image Scan Setup window as well (figure below). When you click Save in the Image Scan Setup window the value will be updated. The Speed in the Image Scan Setup should always be lower, not higher, than the Max Image Scan Speed calculated by the Line Trigger Interval.  As a general rule we want to stay at 8 cm/s or higher value to maintain core flow in the lab.

 

After you done a few calibrations you will develop a feel for what is possible with current camera set up but if you are just starting we recommend setting the line rate to emulate a scan speed of 8 cm/s.

 

CHANGING EXPOSURE VALUES

Now you are ready to start setting the exposures for the RGB channels.

1. Turn on the lights.

2. Click the START GRAB button (Figure 18).

Figure 18. Start Grab.

 

3. Move the camera over the White square on the Xrite Color Checker standard. 

4.  Use the mouse and draw a ROI (Region of Interest) with only the white square inside (Figure 19).  The RGB values and Ratio values will only be calculated for the pixels inside the ROI (Figure 20). Place the cursor in the white square, right-click and draw a rectangle by dragging diagonally.  Release the mouse when you have selected most of the white bar. The rectangle (marked in green) should only have the white color and nothing else inside.

Figure 19. Selecting the ROI of the White square.

 

Figure 20. RGB and Ratio values calculated from the pixels in the ROI.

 

5. Go to the Gains-Black-Shades-Flat tab and click the Clear All Gains and click Clear Black Gains if not already done.

6. Go to the Rates and Exposure tab and set the Green Lock to Off. That step allows you to adjust the exposure intervals (Figure 21).  


Figure 21. Set Green Lock off.

 

Weakest RGB Channel

It is helpful to know which RGB channel has the lowest intensity because this channel will be the limiting factor when setting exposures.  To find which channel is the weakest remove all gains and set identical exposure values for the RGB channels.  The intensities will look like the figure below. Onboard our weakest channel is Blue. 

 

 

7. Start with the blue channel (the weakest channel), increase the Exposure Interval time until Blue value is near 240.  

8. Adjust the green exposure interval until the blue/green ratio is near 1.000 (+/-0.005). 

9. Adjust the red exposure interval until the red/green ratio is near 1.000 (+/-0.005).

10. Click Lights Off. Once you have initially roughed in the RGB channels for the White Color Checker square, it is time to look at the black (dark) corrections.

Note: The Line Trigger Value must be greater than the Exposure Intervals for Red, Green, and Blue.

 

If you cannot get the blue channel to 240, you have several correction options:

1) Lower the lights for increased illumination.

2) Open up the f-stop for more light.

3) Increase the line rate (slower scan speeds) so that you can increase the exposure period.

4) Use gains to amplify the signals.

Using gains to amplify the signal is the simplest choice because the other options are not practical or desirable. The down side of using gains is that they amplify both signal and electrical noise.  Amplifying noise is not good so use gains sparingly.  In the next section we discuss how to use the gains but remember you will likely move back forth between setting exposures and gains to optimize the camera.  It is an iterative process.

 

Neutral Balance - is the Xrite color checker neutrally balanced?

Note that the RGB values for the White square are R=240, G=242 and B=235 for the 2019 Xrite color checker standard. Thus the ratios for B/G and R/G are not 1.000 (as we describe to achieve in steps 8 and 9 above).

B/G = 0.97, R/G = 0.99 (Xrite color checker v. 2019)

Previous color standards used onboard had balanced RGB values, meaning the R, G and B were equal, hence achieving B/G and R/G rations of near 1.000 was the goal. With the 2019 Xrite color checker these values are not balanced for white so achieving 1.000 may not be the ideal ratio for color balancing. 

What ratio is best to use needs to be tested. It may not make any difference, but when time allows we should test update this User Guide if any difference is found in the calibration curve.

 

Setting Gains

 

What are gains?

What is the difference between regular gain and the black gains? Think in terms of a linear calibration where the regular gain sets the slope (multiple) and black gain sets the offset (addition).  So changes in the the regular gain value will have little affect on dark colors but changes in the black gain will offset all colors equally.  The gains labeled "Master" are applied to all channels while the red and blue apply corrections to only those channels.

White Balance via Master Gain Correction

1. Open the Gains-Black-Shades-Flat tab (Figure 22). 

2. Increase the Master Gain until the the Blue value is near 240. 

3. If the other Red and Green values are too high as a result of increasing the Master Gain, you can apply negative gains to those channel until the R/G and B/G ratios are back to near 1.000 or you can re-adjust the exposures.  Re-adjusting the exposures is preferred. 

Once you have initially roughed in the RGB channels for the White Color Checker square, it is time to look at the black (dark) corrections.

Figure 22. Adjusting Master Gain to bring the Blue values up to 240.

Setting the Black (Dark) Values

1. Turn on the lights.

2. Click the START GRAB button.

3. Move the camera over the black square on the ColorChecker standard. 

4. Use the mouse and draw a ROI (Region of Interest) with only the black square inside.  The RGB values and Ratio values will only be calculated for the pixels inside the ROI (Figure 23).

5. Adjust the Master Black value unit the Green value is near 15. 40 is a good starting value for  and we  increasing to 60 works best.

6. Adjust the Red Black and Blue Black Gains until the ratio are close to 1.000 +/- 0.05. The RGB values of the Black square is balanced (R=50, G=50, B=50) so achieving a ratio of 1.000 is best.

Keep an eye on the histogram graph on the bottom left corner (Figure 23). We want all the colors to overlay each other pretty closely. Adjusting the RedGain and BlueGain will move the colors (histograms) in the graph in the lower left, move until they are over lapping.

Figure 23. Adjusting Master Black, RedBlack and BlueBlack to reach RGB values of 15 for black square.

 

Adjusting gains likely changed the RGB values in the White square of the Xrite Color checker. Move the camera back over the white square. Draw an ROI box in the white square. If the values aren't near 240 go back to the Rates and Exposure tab and adjust the the gains values. Check back in the Black square and see its still about 15. Adjust the gains and/or exposure intervals until the Black RGBs read near 15 and White RGBs read near 240. This is a balancing act and can be tedious. Remember do not let the temperature to go about 39°C white doing the balancing.

 

The Problem with Black

The issue with black is that there is very little energy at this level and noise makes up a significant % of the value.  The next issue is that the cameras response from bright to dark objects is non-linear.  The ColorChecker value is actually near 50 but do not try to obtain that value by jacking up the gain.  It just doesn't work!  By convention we aim for RGB values of ~15.

Getting a white balance is also difficult.  Once you set the green to 15 move the camera so that you view the color just above the black and use the red and blue black gains to get a good white balance.

 

Pixel Black, Shading and Flat Corrections

We apply three corrections Pixel Black, Shading and Pixel Flat (gain). Only do the corrections after you have finished the first "rough in" adjustment of the RGB exposure and gains. Obtain the heat resistant silicone gray mat from the drawer PP-2B. The heat resistant silicon mat is homogenous in color which is helpful for the corrections (no mottling as seen in the old grey cardboard card).

Pixel Black Auto Correction: The pixel black level represents extra energy (dark noise) in the camera independent of a light source and is a consistent pattern in the sensor. To correct for this the light source must be turned off and the camera internal correction circuit collects a few lines of data. An average is taken across the line, and pixels are either added to or subtracted from in order for each pixel to have the average value. (Vendor Manual Reference)

Shading Correction - Flat Method: Shading effects can come from an uneven distribution of light and along the outer edge of the camera lens. Shading is corrected for by averaging the signal across a group of eight pixels to represent the line.

Pixel Gain Correction - Flat Method: Each pixel has a different response to a fixed light source. To correct for this non-uniformity a couple lines of data are calculated and the average response of the pixels are calculated. Then each pixel has a correction factor applied to bring all pixels to the average level. The Pixel Gain Correction also corrects for some shading effects and should be done after the shading correction. 

Image Streaking

Image striking is caused when used a non-uniform standard for the Pixel Gain Correction correction or just from dirt.  Until we found the silicone sheets we would have to defocus the lens to mitigate this issues.  If see streaks chack your target material and repeat this correction.

 

Pixel Black Auto Correction

1. The new light set up makes adding a lens cap difficult so it has been decided and tested that the pixel black auto correction can be done without the cap. But Ensure the lights are off.

2.  With lights off click Pixel Black Auto Correction. The RGB lines in the Profile graph should be uniform (Figure 24). 

 

Figure 24. Pixel Black Correction applied.

Shading Correction

  1. Take the heat resistant gray silicone mat and wooden board from the SHIL calibration drawer. Clean off any dust with a piece of tape (Figure 25). Dust will cause unwanted artifacts in the image. The mat must be clean and flat on the track.

  2. Place the heat resistant gray silicone mat on the track. Make sure that it is level and perpendicular to the camera’s axis.

  3. Click Lights On, and move the camera over the gray mat.

  4. Note for Tech: previously we defocused the lens to preform the Shading correction. That is no longer needed because the silicone mat is even in color/texture.

 

Figure 25. The Gray silicone mat being cleaned with tape.

5. The RGB lines should first appear “bowed” evenly across profile and centered in the image (Figure 26).  If not check the orientation of the gray mat, it needs to be flat and perpendicular to the camera.  This very important. A wooden holder was designed to hold the mat, it should be in the SHIL calibration drawer. 

 

Figure 26. Grayscale card corresponding RGB Profile visible.

 

6. Click the Shading Correction - Flat Method button. This can take a few seconds, don’t click anything else until it is done. The RGB lines should now be flat (Figure 27).

 

Figure 27. Image grab and profile after the Shading Correction has been applied.

 

Pixel Gain Correction

1. Make sure gray silicone mat is flat.

2. Click Lights ON

3. Click the Pixel Gain Correction - Flat Method button and move the camera slowly back and forth. This averages the pixels and helps eliminate streaking in the image. This will take several seconds, don’t click anything else until it is done.  When its done the RGB lines should still be flat and the individual RGB the same, but may not be equal to each other.

 

IMAGE Calibration (Correction)

Before we can begin the calibration process, an uncorrected image of ColorChecker standard must be taken.

1. Place the 3D calibration standard on track as shown (Figure 28). Be sure to use the XRite Color checker 2019. The color squares must be oriented as pictured below, butted against the red reflection bar.

 

Figure 28. Color standard in track in correct orientation.

2. Open IMS and Click Start.

3. Scan the STND Color barcode label (Figure 39b). Check the ColorChecker Standard box (Figure 29a). With this box selected no corrections are applied to the image so we are able to assess the raw image quality.

4. Click Take A Picture.

5. When the image has finished click Crop and then Save. We use the uncropped tif image so the crop here is not important.

 

Figure 29.  a) sample information screen with ColorChecker box checked, b) standard barcode being scanned.

 

 

 

6. On the main IMS panel select Instruments and Camera: Image Correction (Figure 30).

Figure 30. Image Correction command selection.

 

 

The main Image Correction window displays three main areas (Figure 31):

A. Graph panel: Main graphical viewing area on the left side of the screen. 

Uncorrected Image Tab: Shows the measured red, green, and blue values of the gray scale color squares.

Applied Corrections Tab: Applies polynomial fit corrections to the RGB lines.

Compare: Shows a visual and RGB values of the Original color square before corrections, the Xrite Color checker standard and of the color after corrections are applied.

B. Image Viewing Panels: Area in upper right portion of the screen that displays the original and corrected test image and Xrite color checker.

Original: Displays the uploaded tiff.

Corrected: Displays the uploaded tiff with corrections applied.

Color Checker: Displays the known values of the Xrite Color Checker.

C. Correction Panel: Panel in the lower right portion of the screen that allows user to apply corrections to the image

TIFF Correction: Shows tiff red, green, and blue polynomial fit.

JPEG Correction: Shows brightness, contrast, and gamma settings.

 

Figure 31: Image Correction user interface. 

 

7. On opening of the Image correction window the program prompts you to select the TIFF file of the color standard you took. The image loads into both the Original and Corrected windows. 

8.  Draw a ROI box loosely around the color checker in the Original box (Figure 32-1)

9. Click Crop (Figure 32-2).

10. Draw another ROI box around the Color Checker squares and this time making sure to only have XRite color checker in the box. White squares will appear inside each square. Adjust the box to get those white squares close to the center of the color squares. Do not click Crop again.

11. Click the colors you want to use for the correction curve (Figure 32-3). As of Nov 24, 2021 use only the white, shades of grey and the black.

 

Figure 32. Image Correction Window. 

 

 

Check TIFF and JPEG Corrections

Here we check and adjust, if needed, our TIFF and JPEG Corrections. You may find you only need to slightly tweak the values and the calibration is good. With the new lights we have found that no adjustments have been needed. However if the image appears streaky, a physical change has happened to the Camera or lights, the RGB values between corrected and expected are far off (>5), or the graphs of either the tiff or jpeg don't look good, you will need to re-calibrate following the full calibration discussed below.

TIFF Correction Check

1. Click TIFF Correction tab (Figure 33-1).

2. Click Uncorrected Image tab. This graph shows the measured red, green, and blue values of the color squares.

3. In the Tiff Correction tab adjust the LUT polynomial order values for the Red, Green, and Blue channels (Figure 33-1). Adjust these values to create the lowest residual error with the smoothest curve in the Uncorrected Image tab. Polynomial values should be about 3.  Make sure that the curve does not wave about too much. If it does, the values need to be lowered.

4. In the Compare tab check that the corrected color square and Xrite color checker RGB values are very close (Figure 34).  Make sure that the white does not exceed the Xrite values (RGB = 240, 242, 235).  There is also a visual display so you can see the difference in color for the color checker and the corrected. If you are unable to produce a reasonable correction curve, it is necessary to redo your white balance correction described in the Calibration section below.

 

Figure 33. Tiff Correction

Note: the TIFF correction is applied to both the TIFF and JPEG image but for the JPEG image you can also apply a Brightness, Contrast and Gamma (BCG) correction (See JPEG Correction section below).  This is done at the photographer’s discretion. With better balanced LEDs on the new light system you may not have to use the BCG corrections (leave the values at their mid-points. Figure 34).

 

Figure 34. Use the Compare tab to view the RGB values for the Xrite color checker and the corrected.

 

JPEG Correction Check

In JPEG correction you will check and adjust, if necessary, the brightness, contrast and gamma (BCG) of the image. Situations may also arise where a JPEG correction should be applied. In the instance of very white or very dark cores, the TIFF images may look good but the JPEG images may look washed out or too dark to view details. JPEG corrections do not alter TIFF image settings. As mentioned above, with the new lights the BCG values may not need to be adjusted and to be kept at the mid values (Figure 35).

1.  Click JPEG Correction tab (Figure 35-1)

2. Adjust the Brightness, Contrast, and Gamma levels (Figure 35-1) to achieve a straight line in the Applied Corrections tab and the RGB Corrected values in the Compare tab should have values near 242 for the white square and near 50 for the black.  We want a linear relationship between the measured and given values. Each BCG setting adjusts the line in different ways and there are many different ways to adjust the values to achieve a linear relationship. You want to achieve a good image with good brightness, where the image has good saturation and not too washed out. The Applied Corrections Graph should be a straight line and the ROI Corrected box for the color selected (Figure 35-2, 35-3) should have values near the RGB values of the Color Checker STND. These may change depending on the instance of extreme colors, extremely white or extremely dark cores, in which the settings may have be tweaked more to get a user friendly consumer image. 

3. If the values are good and there are no streaking issues in the images or other unwanted artifacts, you can click Save and no further adjustments are needed. However if you have determined the doesn't look good, click Cancel and you can proceed to the following Calibration section and complete the calibration instructions listed.

 

Figure 35. JPEG Correction using Brightness, Contrast and Gamma. 

 

 

 

Image Check on Calibrated Monitor

Check the final scan:

1. To double check your calibration under the same scanning conditions as the scientists see, scan an image of the 3D standard without the color checker box selected.

2. Click Crop and Click Save

3. Copy the image to a shared network folder to view on a calibrated computer screen in the Imaging Office. Images located in the C:/DATA/IN/IMAGE folder.

4. Open the TIFF and JPEG in Photoshop in the Imaging Office (calibrated computer).

5. Visually examine each file you just preformed to ensure the colors, neutrals, mid-tone and contrast are true to the real values, and that the scan is free from artifacts. Use the eyedropper tool in photoshop to see the values of pixels (Fig. ## Figure needs to be added).

 

 

C. Set Measurement Parameters

a) Instrument Setup

  1. DAQ > Image Capture Motion Setup (Figure 36)

Figure 36. Image Scan Setup window

 2. Instruments > Camera: General Setup (Figure 37).

Figure 37. General Camera Setup window

3. Instruments > Camera: JAI Camera Setup (Figure 38).

 

Figure 38. General Camera Setup fixed Settings

 

b) Set Measurement Parameters

Adjust measurement parameters before beginning measurements. Users can adjust the RGB settings and camera speed.

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