This article discusses how to match start/end frame colors with precision.
Matching colors of JPEG endframes and videos can be tricky as video compression and image compression work differently. In addition, computer monitors vary widely in color profile so a matching endframe on one monitor can appear differently on another monitor.
The easy way to match a startframe or endframe is to use the "Auto Endframe" feature. Simply include the frames as a first and/or last frame in your video file, and Addroid will do the work for you.
If you prefer to do this manually, to achieve the best possible color match, Addroid recommends the following best practices:
1. Create the JPEG endframe from the final frame of the video.
- Using Adobe Photoshop, open the MOV or MP4 video file.
- Scrub to the final video frame.
- Select all (CTRL-A).
- Save the JPEG using “Save A Copy” and select “9” on the quality scale.
2. Upload the video and JPEG assets and preview the creative.
- Create a new Creative in the Addroid platform.
- Upload the JPEG and video file to the Addroid platform and wait for encoding to finish.
- Click “Save and Preview” to view the new Creative.
- If a color shift occurs, then continue to Step 3. If not, then no further optimization is required.
3. Optimize JPEG in Photoshop and upload.
- Observe the color shift on the Addroid preview page
- Open the JPEG file in Adobe Photoshop and adjust levels to correct the color shift.
- Save the file and ensure the file size is compliant with the guidance below.
NOTE: The Addroid platform will automatically compress JPEG files that are larger than a pre-determined threshold. This is to ensure ad serving is compliant with IAB standards.
You can view the pre and post compression filesizes on Addroid by clicking the small arrow next to your JPG on the creative builder interface and choosing "File Info". Your initial size is on the right side, and the Addroid compressed size is on the left:
The platform will not compress files smaller than the file sizes below. If your ad size is not shown, use this formula to determine the size:
JPEG size threshold formula: Size (Kb) = [ 0.45 * (Ad height) * (Ad width) ] *1000
|Ad Width||Ad Height||Recommended Size (Kb)|
- Upload the new JPEG and set as the current endframe in the Addroid platform.
- Preview creative. If color match has been achieved, then no further adjustment is needed. Otherwise continue to Step 4 below.
4. Repeat Step 3 above until desired color match is achieved.
Why is this so tricky?
Most video formats (nearly all) do not allow ICC color profiles to be embedded. Video on the consumer end is intended for the REC.709 color space. sRGB is similar and uses the same primaries. Transcoding, including compressing, will almost always result is a slight shift in color accuracy, saturation, gamma curve, or black and white level shift. This is made worse due to converting between RGB and YCbCr color spaces.
This means we can't match the colorspace of your video to that of your jpeg endframe. There will always be a slight shift in color.
For additional questions about color matching, email firstname.lastname@example.org.