|portal.htm → linux.htm → gimp_versus_photoshop_1.htm||
by fravia+, with the help of stream304 and others
First published at searchlores in May 2008
Bag of tricks
Feathering •• General cleanup
Sharpening •• Local contrast
Futuristic & Russian avantgarde
Black and white with color
Make Background transparent
Reflections •• Vignettes
Tutorials & books
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If we have the GIMP, why do we need photoshop?
(in fact both are not quite comparable, because of their different targets)
|In short, if we would attempt a (rather useless)
Gimp would win in web graphics, because it's born for the web: more effective compression, higher quality,
more web related operations.|
Photoshop would win in big pictures management: its ad hoc algos are 10 times faster, as you notice when using -say- a 50,000*20,000 pixels image, and its CMYK support is intended for high end "gigantic" paper publishing.
Conclusion: They are not quite comparable, because of their different targets. In other words: The Gimp will do everything outside of commercial printing. If you're not producing a print publication... use the Gimp. Unless you want to pirate software, there is no reason to use Photoshop..
put the swipe on the right, where it feathers naturally into the ragged text, or on the bottom (or top) of the page, not on the left!
You can also use an oval: it creates a soft spot- light that places focus on the image.
Hard edge: lasso ÷> cut
Soft edge: lasso ÷> select ÷> feather ÷> cut
With selective Gaussian, you have two options, Blur Radius and Max Delta. You may lock these two values together, and/or you can play with them to your liking.
Since this is such an intensive computing process, you'll probably want to UNcheck "preview" as you experiment, otherwise if you use the mouse to change values, the process computes each time you change the values.
Values: Blur Radius - 3 to 12; Max Delta - 3 to 12
You can start out with something like 7 & 7 and move up or down from there. Remember to UNDO your changes first, if you want to try a different set of values
Filters ÷> Blur ÷> Selective Gaussian Blur
Blur Radius - 3 to 12
Max Delta - 3 to 12
However, if you perform a selective gaussian blur to reduce noise, you still may want to perform a slight sharpening as your last step in the workflow. What you don't want to happen is to start sharpening those artifacts you were trying to get rid of in the first place.
Normally, all images, or specific areas within images, need some amount of sharpening due to the way a camera dulls the edges of objects during the capture process to help avoid moire-patterns or other artifacts. Foliage in particular seems to "pop" to life after you've applied a small amount of sharpening yourself.
Filters ÷> Enhance ÷> Unsharp Mask
(Unsharp Mask: Just like Gnu's not unix, Unsharp Mask actually sharpens your image. It is a holdover nomenclature from the printing industry)
Radius = 0.5
Amount = 0.5 v
Threshold = 0 (4 or more if you use selective gaussian blur)
Applying local contrast is very easy. Just bring up Unsharp Mask Code: and set the RADIUS value to a ridiculous value of 60 (sixty), set the Threshold value to 0 (zero) and change the AMOUNT to anwhere from 0.07 to 0.15 (or maybe a little more) according to your tastes.
Local contrast "brings some 3d-pop back into most images"
Filters ÷> Enhance ÷> Unsharp Mask
Radius = 60
Amount = 0.1
(turn off preview! )
Layer ÷> Duplicate Layer |
Filters ÷> Distorts ÷> Emboss
Azimuth = 0
Elevation = 45
Depth = 1
CTRL+L for Layer dialog and
Layer Mode = Hard Light or Grain Merge (with varying levels of opacity, for instance 2.8)
1. Duplicate the image
2. Using the duplicate open the layers dialog and select "Duplicate Layer"
3. Gaussian blur the top layer, you can experiment to find good values, try 6x6 pixels and go from there.
4. Invert the top layer Layer ÷> Colors ÷>Invert
5. Blend using the layer dialog to 50%
6. Flatten the image.
The dupe will now be your high pass filter image.
Layer ÷> Duplicate Layer
Filters ÷> Blur ÷> Motion
Length = 27
CTRL+L for Layer dialog and
Layer Mode = Difference (with high opacity, for instance 83)
Duplicate your image: Image ÷> Duplicate|
Blackandwhitize the new copy: Image ÷> Mode ÷> grayscale
Make a copy in Memory of your gray image: Edit ÷> Copy
Back to color image: Add a transparent layer: Layers ÷> New Layer
select Transparency as your Layer Fill Type
Paste your black and white image from memory to new layer: Edit ÷> Paste
Anchor the image: Layer ÷> Anchor Layer (in gimp layers float)
Now erase ONLY the parts of the black and white image that you want to have in color
You have a photograph or image of something on -say- a white background, and you would like to make that background transparent so that you can lay your image onto another, different, image.
Convert the image to RGB mode if it's not already
Select the white region by color: Select ÷> Color
Select by ÷> Composite
Threshold ÷> around 15
In the Layer ÷> Transparency menu, add an alpha channel
In the same menu, set "Color to alpha"
This will make the white background to transparent
Save as png file
Copy and paste your "top part" inside a new image (double height)
Duplicate its layer: Layer ÷> Duplicate
Vertically flip the new layer: Layer ÷> Transform ÷> Flip vertically
Position (move) the new flipped layer under the original one: Use "move" tool
Very important: right click the flipped and moved layer and select "Add Layer Mask"
Also select the option "White(Full opacity)"
Make sure that the flipped layer's mask is selected and choose the Gradient Tool
Make sure the selected colors are Black and white
Use the gradient tool "dragging" from the bottom towards the top in the middle of your flipped image.
You can also additionally 'shorten' and 'skew' the reflected layer with|
Tools ÷> Transform Tools ÷> Scale (only modify: scale ratio Y)
Tools ÷> Transform Tools ÷> Shear (only modify: shear magnitude X)
Rectangle select tool ÷> selection of frame|
click on the quickmask icon (lower left corner of any image)
Filters ÷> Noise ÷> Spread
Horizontal = 16
Vertical = 16
Toggle quick mask off (lower left corner icon)
Select ÷> Invert
Edit ÷> Fill with BG colour
using different filters:
the slices will have a built-in unity of color and texture, allowing
them to work easily together|
Up close, an ordinary image is a surprising potpourri of lines, shapes, colors, curves, corners and edges.
In the example note how you can geometrically relate (or even combine) totally different parts of the same image using its own colors and textures.
Learn by doing