AIM: CRT Slew Rate Compensation filter

Accurate Image Manipulation for Desktops

# CRT Slew Rate Compensation (10th, Oct., 1999)

# Description

> This is a highly dedicated filter for images that are shown on CRT monitor. Do not apply over original image, publish a copy.

> All CRT monitors have problem with the slew-rate or signal stabization in the horizontal direction, but not in the vertical direction. The Monitor Signal Conditioning Graph on the above page shows this problem well (this filter can be applied over that graph to see if it works, just convert the gif to RGB mode and apply the filter).

> The filter looks edges on each horizontal line and compensates it by a special algorithm. It does what it does rather well, the only thing that it can not compensate is a 0/255 edge since the signal is already at min/max limits.

> The effect is not large, but the filter does correct the CRT imperfection to great extent, the image will appear more natural and "airy" rather than "closed".

# Selection Dropdown

> None.

# Sliders

> Amount, 0...160. Based on a very large evaluation the default value 80 seems to be a very good average. CRT monitors seem to be quite similar in respect to this problem.

# Notes

> This filter works properly only when applied over linear images. It should be applied over the final copy just before the output compensation.

> First thing to do when the filter opens is to Shift-Click the preview + button in order to have the 1:1 zoom in the preview box. Then drag the image so that a representative area is shown, the dragging is not limited to the preview box boundaries.

# Author

> Timo Autiokari. Homepage: Accurate Image Manipulation for Desktops

# Usage and Distribution Rights

> Free to download and use, distribution prohibited.

# Filter Engine

> FilterFormula v 1.1, by ATS/Graphics