Difference between revisions of "GIMP/C2/How-To-Fix-An-Underexposed-Image/English-timed"

| 00.23

|Welcome to  Meet The GIMP. My name is Rolf steinort and I am recording this is Bremen, Northen Germany.  

| 00.32

| I have got this image with an e-mail from Norman. He asked to save it.  

| 00.39

|This is the image he has got after using raw convertor and this here was the original image.  

| 00.48

|Comparing the images it was clear what Norman has done. First he has rotated the image and then he has edited the image with the curves tool to get the colors and brightness in the foreground right and tried not to darken the clouds.  

| 01.09

|When you look at this image here the clouds are simply gorgeous. I love them and I have asked him for permission to show this image on the show and I will try to re-do his work now and then I’ll try to get the cloud better in his image.  

| 01.33

| But first let’s see if we find something in EXIF information about this image which gives clue to what went wrong .  

| 01.43

|You can see that it’s a Panasonic camera, and this camera has very tiny sensor. You can put this camera in your shirt pocket.  

| 01.58

|And here we have the exposure data.One  thousand of a second exposure time and Aperture is 5.6. The flash was on and the camera calculated the effect of the flash into the image. And the flash of such tiny camera does not work with such a scene. I think you would need something like a small nuclear bomb behind you for brightening up this part of the image.

|02.36

| This image is saved in JPEG and that gives another problem. This area here which is the really interesting part in this image has become is very dark because of JPEG compression. And when I zoom into the horizon I can see a well defined stuff but a bit over sharpened and there is also a ship on the horizon.

|03.08

| The clouds are very detailed but when we go into the dark part you see a tree here but nothing is clearly visible. This is because JPEG leave parts out of the image which computer program in the camera doesn’t think you will ever see.  

|03.32

|03.45

|And when you shoot this raw you avoid such problems and in next tutorial I’ll show you the UF raw converter and how to use it with the gimp and I think that will be the right topic for the next tutorial.  

| 04.06

|I load the image into the GIMP by just pulling it over to the tool box here and enlarge the window. Now my first step will be sizing this image a bit because the image is so large that the resulting ‘XCF’ file will be more than 40 mega bytes. Sizing down can be done by clicking on image in the tool bar, selecting scale image and I change the width to say 1000 pixel and when I press tab I get the height as 750 pixels and I have the best interpolation selected so I click on scale .  

| 05.01

|Press shift +ctrl+ E to get the image full into the frame here and now I am set for editing this image.

| 05.11

|The first step will be rotating. In previous tutorials I have shown you two ways to rotate an image and today it’s time for 3rd way. So I follow the same step of zooming into the image where I can see a horizontal line and the horizontal line is on the horizon because horizon by definition is horizontal.  

| 05.39

|Then I select the measurement tool from the tool box and I don’t select the info window because it pops up in between the image frame but I can get all the information here below in the status bar.  

| 06.01

|Now getting the angle of horizon is simple, just put cursor on the horizon, press the mouse button and pull it. Pull the line to the other side and make a line parallel to the horizon and release the button. Look for the angle info in the status bar and I see here the angle is 1.64°. Now I select the rotate tool, just click into the image and type in -1.63°(degrees), minus because I want to counter the plus 1.63 °(degrees). Click on rotate and you get a rotated image.  

| 07.05

|Just to test the horizon we pull down the scale and it is horizontal.  

| 07.14

|The next step will be cropping the image but I can’t crop the image now because this part of the image is not visible so I really can’t judge the stuff. I don’t know where to crop ,so first make this part of the image a bit brighter.

|07.43

|I want to work with the curves tool but before that I make a copy of the layer. Because when we use curves tool ,information in the image is lost. So never do something with an image which you can’t take back. Well I did rotated but in later steps never do anything on original image.  

|08.08

|1st I’ll edit the Land portion so I call this layer Land and double click into the field where the name exists and press return. Now the layer is named Land. .  

| 08.25

|I select the curves tool, click into the image and now I will explore the image.  

| 08.34

|This part of the image is really the darkest part, one can make it out easily but the grass here is also very dark. The water seems to be this part of the gray scale here and the sky is obviously this part.  

| 09.01

|So I have to brighten the land in the image and I just do it by pulling this up.  

| 09.15

|Now the question which comes to mind is how far should I pull it because when I go too far it will look artificial. And if I want to combine the sky and the land with big differences in the curves ,it will not look like a real image. So I pull this down a bit . Let me try this.  

| 09.49

|This looks good here. The sea is not too bright and the chapel is also visible. So I click on OK.

| 10.06

|After I have edited the land part, let me go to the sky. So again make a copy of the original layer and just move it on the top and name it sky. Double click on the layer, type the name as sky, pressing return and we have the sky. I want to edit only the sky layer without harming other layers and to do that I work with a layer mask.  

|10.37

|Right click on sky layer, click on add a layer mask and select white layer mask i.e full opacity that means this layer is fully visible and it is white.

| 10.54

| 11.07

|A gradient is simply a thing between black and white. Let me show you this in a scrap layer here.  

| 11.34

|I have selected the gradient tool and this is the new thing I have just found out by accident that when you double click on the tool icon, the tool options are automatically selected. I don’t think it’s a new thing for you but it’s new for me.  

|11.56

|11.59

|Going back to the gradient tool, when I pull this line here by clicking the left mouse button and release it. The area to the left of the starting point is filled with black and the area on right of the end point is filled with white which is the other side of the gradient. And the area between white and black is the different series of grays and it is called gradient.

|12.38

|And I can make long gradient or very short gradient, here are the different gradient tools and I will stick to this one here black and white and there are lot more options here like radial where you can make circle. There are lot more options which you can use.  

| 13.10

|Its worth to explore these options of this tool. So I set the shape to linear and I delete the scrap layer here. Now I am working on the sky layer here, the gradient is set from black to white, from making the image transparent to revealing the image and I go back to the layer dialog and check if I have activated the layer itself because I don’t want to paint in the original image. I want to paint the layer mask.

| 13.59

| And select the zoom tool to zoom into the image

| 14.04

|14.14

|I will start at this point here and end here. I want to have the gradient straight because gradient in this way would result in such an image which I don’t want. Press ctrl + z to undo the step.  

| 14.37

| So I press the control key and now the movement of the slider here is limited to 5 degrees.

| 14.49

| 14.58

| When you go back to full image you can see that this is my gradient. And when I switch off other layers, only the upper part of the image is visible in the top layer and others are in the background.  

| 15.23

| But I don’t think this looks very convincing. This looks a bit artificial so I want to make the sky a bit brighter now.  

| 15.34

| For doing that, first I have to deactivate the layer mask and activate the layer itself for working on it otherwise I would have used curves tools on the layer mask. You can always identify the active part of the layer by white frame around it.  

| 15.56

|So les try this here.

| 15.59

| Now we want to brighten the sky so I am pulling this up.  

| 16.12

| 16.29

|I think this will work. So let’s compare the image by switching of the sky layer and layers below it. You can see the difference.  

| 16.46

|This is the original image. This layer is the new sky and this is the new land below. The land could use a bit more of contrast I think but I am not sure so I’ll have to try this. So simply double click the land layer and select the Overlay mode which gives you a bit more of contrast but this is definitely too much so I slide down the opacity.  

| 17.25

| 17.33

|Now I have got four layers. The background, the original image which is not really needed any more, the land layer, a land copy and the sky with the layer mask. 

| 17.50

|And I can change all these values here without loosing the image information.Thats the great advantage of using layers

| 18.03

|Now for the last part cropping, Norman wanted to crop it into 7: 5 ratio because his printer uses 7/5 inch paper.  

| 18.18

| So lets do that ,7/5. A fixed aspect ratio .  

| 18.27

| Where to crop?? I think I forgotten where Norman cropped this image. So lets decide here. 

|18.36

| I think the tree should be included. And the dry grass should be included.  

| 18.43

| So I have to start here at the right corner and just pull up. Crop tool.  

| 18.58

| This is simply the matter of taste and nothing to do with pumping , one could learn. There are rules of thirds. Let me put this in .  

| 19.13

|Here you see the front side of the chapel is now one of the points of interest. Here is the more artistic, golden section and it can be helpful but I think the best is simply your eye .  

| 19.33

| 19.37

|I want to save his image as a JEPG image. And before that I have to sharpen it a little bit.  

| 19.47

|The traces of sharpening that were visible before I did all my manipulations are gone. White lines were visible to see hallows.  

| 20.00

|I think this time also i'll use the filters/ enhance(sharpen method) 

| 20.16

|This is basically an unsharped mask, sharpening with some standard values pre-set. I will cover the unshaped mask in the later tutorial.

| 20.30

|I have never use that and for that I have to learn it myself. So that I can explain something about it.     

| 20.44

| 20.50

| 21.02

| 21.10

|Ok I know that jpeg cannot handle image with multiple layers so the image is now exported and all the layer information is lost. And gimp just gives a warning. And I think 85% quality is good. 

| 21.31

| 21.39

|And now I can go back with my sharpening and resizing the image to something that I could put in my blog for the show note.  

| 21.55

|Go to image/ scale image and I want width of 600 pixels.  

| 22.08

|Just scale it .  

| 22.11

|And now I sharpen it again, sharpening should be the last step in your chain of things you do to an image. It is really the last step.  

| 22.33

|The algorithm works well only if you don’t change anything after that. No resizing also.  

| 22.41

| 22.47

|I think I can have bit more. Ending basically on the same amount.  

| 22.57

|I am ok with this image now. I save this as .(dot)600 so that I can know which image to put in the block later.  

| 23.20

|Lets compare the 2 images. This is the one Norman made and this is the one I made.  

| 23.30

| 23.40

| 23.47

|I think I have over done a bit with the brightening here.  

| 23.54

|Well here i am back  to fix the sea layer in easy way.  

| 24.00

|I make a copy of original on background layer.  

| 24.06

|Rename the layer to sea.  

| 24.10

|Now I pull it above land copy and below the sky.  

| 24.16

|And you can see now the sky layer is not disturbed by this only the land is disturbed. But I’ll mask that out.  

| 24.27

|To do that I add a layer mask.  

| 24.31

|Right click , add layer mask and now I take a grayscale copy of the layer .

| 24.40

|Now you see the land here its brighter. Its not like it was here but you see biggest changes in the water.

| 24.53

|And now lets work a bit on the layer mask here. Click on show the layer mask. You see it here and switch the sky off.  

| 25.05

|Now I select the curves tool and I’ll adjust the curves in a way that the land gets darker.  

| 25.17

|And sea and sky gets brighter.  

| 25.28

|Now lets look at the image. Unclick show layer mask.

| 25.39

| 25.51

|Now when i select the sea layer you can see that the sea is better. Now I’ll change the values in the image by using the curves tool.  

| 26.09

| 26.16

|Give the sea a bit more contrast.

| 26.24

|Bit like this here.  

| 26.31

|The steep of the slope here is more contrast in the image. This part of the histogram was sea. So I get here a lot of contrast.  

| 26.49

|And just fill around with the curve until it fits a bit.  

 

| 26.56

|I haven’t tried this before so I have to experiment here a little bit.

| 27.10

| 27.17

|Now lets look at the border between the rocks here and sea. I had a big problem there before.  

| 27.28

|So this time I nearly got no visible hallows. And when I zoom into this here.

| 27.41

|You can see something like hallow but its simply surf at the beach here.   

| 27.51

| 27.56

|In my first tries, i tried to get differences between land sea and sky a bit more. I have simply over done it. But this way here I think it works better. So is there anything left to be done?????

| 28.18

| 28.25

| 28.35

| 28.41

|This is Hemant Waidande dubbing for the Spoken Tutorial project