Image Projection

An Epson PowerLite 81p XGA projector is used for Exhibition of digital images at DDPC meetings. The projector has been calibrated for the meeting room with a colorimeter device. Images are projected “full screen” with a black background. Requirements and guidelines for image submission are described below.
1.0 General Requirements

Participants must e-mail their Exhibition image files, as attachments, to the club Projectionist at least two days prior to the Exhibition date – as set forth in the club meeting notice. Digitized images may originate from film or print scans, or from digital cameras. Up to three image entries may be submitted for Exhibition, unless notified otherwise in advance. In addition, “before” and “after” pairs of images may be submitted – each pair counts as one entry. The “after” image should be a new image that shows your adjustments/improvements from the “before” image. Images received by the Projectionist will be used for club purposes only.
2.0 Image Requirements

2.2 File Format and Size: JPG with compressed file size not to exceed 500kb.
Images for digital projection must be no larger than 768 pixels high and 1024 pixels
wide. The images must be in JPG format with a file size no larger than 500 KB.
Entries not meeting these size requirements may be rejected or resized at the
discretion of the Competition Committee.
The title and maker’s name must be
entered into the EXIF metadata for the image or contained in an e-mail or text file
sent or delivered to the person receiving the entries.

3.0 Image Preparation Guidelines

(suggestions based on use of Photoshop):

3.1 In order to match an image on your computer monitor with the image projected on a screen, it is very important that you calibrate your monitor. It is recommended that one of the following calibration methods be used–in order of preference:

* Calibration device, such as a colorimeter;
* Adobe Gamma, a Photoshop feature (This may not work on an LCD monitor);
* Visually to a calibration target image.

3.2 Edit the image as necessary. Do File>Save As to save the edited image in TIF or PSD format.

3.3 Flatten the image if layers were used.

3.4 Size the image. The best image quality for projection is obtained if the width is made exactly 1024 pixels and/or the height is made exactly 768 pixels – in order to match the native resolution of the digital projector. Do one of the following:

* Image>Image Size: Check Constrain Proportions and Resample Image. If horizontal image, set Pixel Dimensions Width=1024 pixels. If vertical image, set Pixel Dimensions Height=768 pixels.
* File>Automate>Fit Image: Enter Width=1024 pixels and Height=768 pixels. This automates what you otherwise have to do in Image Size. This re-samples and maintains the aspect ratio of the image to fit within the specified height and width dimensions.

3.5 Sharpen the image, as necessary, and examine at 100% magnification.

3.6 Use sRGB Color Space: If your normal RGB Color Setting (color working space) is other than sRGB, it is suggested that the file intended for image projection be converted to sRGB via Image>Mode>Convert to Profile. You probably won’t notice any difference in colors after converting to sRGB, but in case you do, re-edit the image as necessary. Digital projectors are typically designed for sRGB color space.

3.7 Create JPG file: Do one of the following:

* File>Save As: File name must start with your last name, followed by the title. For example: York-Aspen Glow.JPG. It is not necessary to embed the ICC Profile in the JPG file, so this box can be unchecked. In the JPeg Options dialog box set the quality level as high as possible – consistent with keeping the compressed JPG file size close to, but less than, 500 kb. For a given quality level setting the associated compressed JPG file size is shown as kilobytes (kb) – the number in the lower left (left of the slash) of the “Size” area.
* File>Save For Web: File name must start with your last name, followed by the title, for example: York-Aspen Glow.JPG. It is not necessary to embed the ICC Profile in the JPG file, so this box can be unchecked. Click the arrow in the upper right to reveal the drop-down optimize menu. Select Optimize to File Size and enter 500 kb, and select Current Settings. Click OK. Click Save.

The advantage of using Save For Web is that you can get closer to the file size limit than with Save As. A disadvantage may be that Save For Web strips out any EXIF/IPTC metadata (such as, camera settings, copyright, author, caption or contact information) that may be in the file – unless you have made a setting in Save For Web to retain such metadata (as in Photoshop CS4).
4.0 Image Submittal Requirements

E-mail your JPG images, as Attachments, to the club Projectionist at the following e-mail address:

fluhman3@comcast.net

Depending on your Internet Service Provider, you may be able to send several image files with one e-mail message. If multiple e-mails are sent, state how many images you are submitting in total.
5.0 Common Errors

5.1 Vertical Pixel Dimension Too Tall: Mistaking the 1024 pixel dimension as acceptable for a vertical (portrait) oriented image. Remember the vertical dimension must not exceed 768 pixels.

5.2 Pixel Dimensions Too Large or Small: Exactly matching the native resolution of the projector (1024 x 768 pixels) results in the best image quality. Images with larger or smaller dimensions would be interpolated by the projector and result in display of lower quality images.

5.3 JPG File Size Too Large: File size should not exceed the 500 kb limit. However, substantially smaller file size results in lower image quality, because the file has been JPG compressed more than necessary. Strive to attain the largest file size without exceeding the 500 kb limit.

5.4 Incorrect File Naming: Remember, it should be your last name followed by the title. For example: York-Aspen Glow.JPG

6.0 Tips

6.1 Stroked Border: If your image has dark regions along the perimeter, the framing of the image may not be distinct when projected against the black background. Adding a narrow stroked border of another color would provide separation.

6.2 Canvas Size: If your image does not fill the full 1024 x 768 pixel dimensions, and you want to have the image viewed with some background color other than black in the “unused” space; you can use Canvas Size to enlarge the image to the full 1024 x 768 pixel dimensions and fill the added space with a color of your choice.