Photoshop CS3 por Jim Hoerricks – LAPD especialista forense …
- Girassol Fotografias
- 28 de out. de 2008
- 2 min de leitura
Muito interessante o que esse especialista faz com as imagens usando o photoshop. Em um dos seus artigos em que ela fala sobre a conversão do preto, branco e cinza. Me faz lembrar da técnica que Ansel Adams usava chamada “Sistema de Zonas“.
Photoshop CS3 Tutorials By Jim Hoerricks – LAPD Forensic Expert
Jim Hoerricks is the Senior Forensic Video Analyst for the Los Angeles Police Department’s Scientific Investigation Division, a Photoshop instructor, an author, and a court qualified expert witness in Forensic Video Analysis. His site, Forensic Photoshop, contains lots of interesting posts and tutorials that deal with using Photoshop for forensic work. Jim established the LAPD’s Forensic Video Lab in 2001, has been the lead analyst on many of the LAPD’s high-profile cases, and helped set the standard by which video evidence is handled by the department. Jim has also written a book, Forensic Photoshop. We are pleased to offer some of his Photoshop CS3 tutorials and articles.
Forensic Photoshop Tutorial – Sharpening in LAB mode
I’ve received a few e-mails from folks asking for a demonstration on sharpening in LAB mode. With this technique, we are going to be targeting just the Lightness Channel – affecting only the lightness values in the image.
In today’s image, detail is important. In a structural failure such as this, I want to highlight the sources of that failure. In this case, the bridge’s details, the torn and twisted metal, the bent rebar, and the broken concrete all have a part to play in the telling of this story. I also want to make sure that the items in the water receive attention.
Forensic Photoshop Tutorial – Custom Filters Explained If you are a fan of High Pass sharpening like me, you’ve probably passed the Custom filter on a daily basis. You may have even opened it up to see what it does. Then, after seeing this spreadsheet looking thing, clicked cancel and haven’t given it a thought since. Let’s take a look at a couple of effects that can be produced using custom filters.
There are times, as an artist or photographer, that I want to create a certain look and feel with an image – warm, hot, cool, cold, and etc. These types of temperature issues can help set the mood and convey a certain message. Look at the images used in advertising and you’ll see what I mean. Johnny Walker’s Blue Label is a different blue than LA Dodger Blue. The difference is in the brightness value (HSB). Dial down the brightness of any colour to cool it off.
In Forensic science, numbers are king. Regardless of my monitor’s state of repair, or my calibration method, if I sample an image I will be able to determine the RGB values for a particular pixel within Photoshop.
Forensic Photoshop Tutorial – Local Contrast Control with the Sponge Tool This tip is a fun one: using the Sponge Tool to control local contrast. To bring out the details in an image, I can use an curves/levels adjustment layer. I can further refine that adjustment with masks. With the Sponge Tool, I can target specific areas of the image quickly. Working on a separate layer, I can apply these edits non-destructively.
Sometimes we find it necessary to convert our images to grayscale. There are a few different methods available to us that yield different results. You’ve probably heard that simply choosing Grayscale from the Image menu is not the best way to go about it. This produces similar results as converting the image to LAB mode then selecting only the Lightness channel. You may have also worked with the Channel Mixer or CS3’s new Black and White adjustment layer tools.
I like Calculations for several reasons. I can use it for masking and I can use it for black and white conversions. By using it for black and white conversions, I have an incredible amount of control over the final look of the image. I also have the ability to create a new document from the results, thus preserving my original. Let’s take a look.
Fonte: photoshopsupport


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