Dana Vrajitoru
I310/D513 Multimedia Arts and Technology

Lab 5

Date: Tuesday, September 20, 2016. Due: September 27, 2016.

Ex. 1.

In this lab we are going to explore some digital image manipulation operations.

Download a photo from the web (or you can use your own photo if you have one easily available).

You can go to www.flickr.com, then to Explore. Scroll down for more photos and choose a color photo. It's better to use a photo that doesn't look as it's been filtered already.

Click on the image you chose.

Next to the image or just below it, there should be a link to download the photo. Clicking on it, you should get available sizes. that lets you select the size.

Choose the largest size that is not more 1024 pixels on either side. Click on it to download, then from the browser, open the containing folder. Move it to a place where you can work on it. Close or hide the browser and open the image with the Gimp.

You can also simply do a google image search with a nature or city (or similar) theme and "no filter".

If you can't download the image for some reason, keep the browser open with the image displayed in it completely and open the Gimp. From the File menu choose Create, then Snapshot. A dialog should open where you can choose to take a snapshot of a single window. Click on Snap and then in the browser window. Once an image of the browser opens in the Gimp, use the Crop Tool (it looks like a knife) to crop the image to discard everything but the photo from the image.

Save the image in xcf format.

Note.

Do not upload this image or the result of any modification you make to it on any web site, unless you start with a photo of your own.

For an example, I will start with this image (www.flickr.com/photos/novia913/4324838509).

Blur - Overlay

You can adjust the colors in the original image if necessary using the brightness-contrast or the curves.

From the Layers dialog, right-click on the background layer and duplicate the layer (there is also a button you can simply click). Rename the new layer "blur". Select the new layer from the same dialog to make it active.

We're going to apply a blur filter to this new layer with an adjustable parameter for the depth of the operation.

From the image window, the Filters menu, choose Blur, then Gaussian Blur. Increase the horizontal and vertical radius of the blur in the dialog that opens to 10, then click ok.

We are going to use the blurred layer as a modifier to the original image.

In the layers dialog, click on the arrow(s) next to Mode: Normal. This should open a menu. Try different options to see the effect, and then choose Overlay.

If the effect is too strong, you can reduce the opacity of the blurred layer.

Save the image (still in xcf), then export it as a jpeg, and add "_blur" to the file name.

Here (golden_state_blur.jpg) is the result of the operation on the image I chose.

Posterize and Page Curl

Flatten the image using the Image menu from the image window.

This should merge the layers and remove any transparency.

From the image window, click on the Colors menu and follow with Posterize. Increase the level to about 6, then click ok.

The ore colors you use, the less the image will look like a poster. You can choose a value that makes a difference without making the image unrecognizable.

From the main window click on the rectangular selection tool.  Select a small region that completely includes the bottom left corner of the image.

The selection will be used for a special effect on the corner of the image, so make sure that the corner is inside it. Zooming out of the image can help making sure of that.

From the Filters menu, follow on Distorts, then Page Curl. In the dialog that opens choose the direction of the curling to be Lower left.

Export the image as a png, and add "curl" to the file name.

Here (golden_state_curl.png) is the result of the operation on the image I chose.

Soft Glow and Edge Detect

Open the original image again (or another fresh one if you want). Save it under yet another name, also in xcf format.

We will apply other special effects to this image that will make it look like it's taken from a comic book.

Duplicate the background layer and rename the new layer "sketch". Make sure it is the active layer.

From the Filters menu choose Edge-Detect and then Edge (any of them should work). Then invert the colors in this layer (Colors - Invert).

The main outlines of the borders should be dark.

You can explore the effects of the various superposition modes in the Layers dialog. For example, this image (golden_state_grain_extract.jpg) was created with a grain extract mode.

When you're done experimenting, select "Darken Only". Save your work.

This should create dark outlines around the main shapes in the image.

Select the background layer again. Apply the filter called Softglow from the Artistic category.

This should add some highlights to the image.

Select the sketch layer again. From the layers dialog reduce the opacity of this layer to about 70% (or to whatever looks good to you).

Save your work as xcf, then save it again as a jpeg image. Add the word "sketch" in the name of the jpg image.

Here (golden_state_sketch.jpg) is the result of the operation on the image I chose.

Grain Extract

Next, we're going to use some filters that can be used to create airbrush effects on portraits for magazines and such.

Start again with a fresh image.

This part works best with a portrait. For example, I will start with this photo (www.flickr.com/photos/merete-haseth/4325185243).

Save the image as an xcf. Duplicate the background layer, then name the new one "blur". Blur this layer with a Gaussian Blur of a radius of 10, then invert the colors in this layer.

You can also experiment with the different merging modes for this layer to see what the effect is.

Choose the mode for this layer as "Grain Extract".

If the effect is too strong, you can decrease the opacity of the layer. This should have the effect of removing or smoothing some of the fine details in the original image.

Save the image (as xcf).

Next, we're going to add some decorations to the image.

From the Filters menu in the image window, choose Decor, then Fuzzy Border. Increase the size of the border to about 25 (unless the image is smaller than 200 pixels on either side). Click on the Color and choose something that fits the colors in your image, then click Ok.

This should create a new image.

In the Filters menu of the new image, choose Decor, then Round Corners.

This operation will create a third image.

Export this last one as a jpeg with "_border" in the name.

Here (yellow.jpg) is the result of the operation on the image I chose.

Note.

You will have to upload the 3 jpeg images and the one png image resulting from this lab as part of the homework (see the Homework 5 or I310_Hw5.pdf) for more instructions).